The bodies representing most European airlines and airports have questioned the need for the unprecedented curbs, which affect millions of travellers.

Airlines that have carried out test flights say planes showed no obvious damage after flying through the ash.

EU Transport Commissioner Siim Kallas said he hoped 50% of Europe's airspace would be risk-free on Monday.

He said the current situation was "not sustainable" and European authorities were working to find a solution that did not compromise safety.

Mr Kallas also said EU transport ministers would hold a video teleconference on Monday to assess the situation. About 17 European countries have closed their airspace.

The flight bans came amid fears that the ash - a mixture of glass, sand and rock particles - can seriously damage aircraft engines. Airlines are estimated to be losing some £130m ($200m) a day.

ACI Europe - which represents major airports - and the Association of European Airlines issued a joint statement urging officials to reconsider the restrictions.

'Dangerous levels of ash'

"The eruption of the Icelandic volcano is not an unprecedented event and the procedures applied in other parts of the world for volcanic eruptions do not appear to require the kind of restrictions that are presently being imposed in Europe," the statement said.

Earlier, several airlines also questioned the curbs.

Peter Hartman, chief executive of Dutch carrier KLM, said there had been "nothing unusual" about a test flight carried out by the airline through the plume, and he hoped to "get permission as soon as possible to partially restart our operations".

Steven Verhagen, vice-president of the Dutch Airline Pilots Association, told the Associated Press news agency: "In our opinion there is absolutely no reason to worry about resuming flights."

Germany's two biggest airlines, Lufthansa and Air Berlin, also said they had carried out test flights without apparent damage, as did Air France.

Air Berlin spokeswoman Diana Daedelow told the BBC: "It is astonishing that these findings... have seemingly been ignored in the decision-making process of the aviation safety authorities."

A British Airways Boeing 747 completed a test flight through the no-fly zone at 30,000ft (9.1km) from Heathrow to Cardiff on Sunday.

While it encountered no problems, no loss of engine performance and no damage to windows, engineers in Cardiff were due to make a more detailed assessment of its engine overnight.

Earlier on Sunday, a UK Met Office plane went through the cloud and encountered dangerous levels of ash, showing that the issue is not whether the cloud is real and dangerous but whether its extent can be accurately mapped, BBC business editor Robert Peston writes.

One possible solution is to put observation planes in the sky, to give a more detailed picture of the location of ash concentrations, and the UK government is therefore trying to obtain more observation planes, from the military in particular, he adds.

Our business editor understands that BA fears it may not be allowed to fly normal services until Thursday at the earliest.

Worsening disruption

UK Transport Secretary Lord Adonis, said "urgent discussions" were taking place between European and international agencies to ease the chaos.

"We want to be able to resume flights as soon as possible, but safety remains my paramount concern," he said.

Weather experts say wind patterns mean the cloud is not likely to move far until later in the week.

Brian Flynn, head of operations at Eurocontrol - which co-ordinates air traffic control in 38 nations - dismissed suggestions the authorities were being over-cautious.

"With the overriding objective of protecting the travelling public, these exceptional measures have to be taken," he said.

Eurocontrol said there were only 5,000 flights in European airspace on Sunday, against 24,000 normally. There was a similar figure on Saturday. All but 55 of 337 scheduled flights by US carriers to and from Europe were also cancelled.

About 100,000 Poles turned out for Sunday's state funeral for President Lech Kaczynski and his wife Maria in the southern city of Krakow. The ceremonies ended a week of mourning for 96 people killed in a plane crash a week ago.

A final day of memorial services for President Lech Kaczynski and his wife, an elaborate holy mass as St. Mary's Basilica in central Krakow.

The church filled with family and friends along with government officials, foreign leaders and delegations. The president and first lady were among 96 people who died when their plane crashed near the Russian town of Smolensk.

They were on their way to a memorial service honoring 22,000 Polish military officers killed by Soviet troops in 1940 in the Katyn forest in western Russia.

Katyn remains a defining moment in Polish history and has severely troubled relations between Russia and Poland. At the funeral, Speaker of the Polish Parliament and Acting President Bronislav Komorowski said he hoped the tragedy of the plane crash may help bring the two nations together.

He said there have been many signs of warmth and understanding from the Russian people and words and gestures from Russia's leaders. These are greatly appreciated, he said.

Russian President Dmitri Medvedev was among the foreign leaders attending the funeral. Before leaving Krakow, he too said he hoped the tragedy might bring about a rapprochement.

Many other leaders had planned to attend the funeral, but were forced to cancel due to hazardous flying conditions above much of Europe, caused by a cloud of volcanic ash in the high atmosphere. U.S. President Barrack Obama was among those unable to attend.

After the funeral mass, the coffins of President Kaczynski and his wife were taken through the town and up the hill to Wawel Cathedral, where they were laid to rest.

Crowds lined the streets, tossing flowers and waving Polish flags, the Cathedral's historic bell tolling a final farewell.

The pope met privately with eight Maltese victims of sexual abuse in the Vatican's embassy in Valletta. A statement issued by the Vatican after the meeting said he prayed with the men and assured them the Church will continue doing all in its power to investigate allegations, to bring to justice those responsible for abuse and to implement effective measures designed to safeguard young people in the future. The statement was one of the clearest yet from the Vatican that it wants local bishops to cooperate with civil authorities in prosecuting priests who abused children. It also stated the pope was deeply moved by the stories of the abuse victims and expressed his shame and sorrow over what they and their families have suffered. Lawrence Grech was one of the abuse victims who met with the pope. He said he lost his faith 20 years ago, but this experience will change his life. "I am more than satisfied," said Grech. "I cannot explain. It is more than I expected, because to meet the pope personally you have to be something special." Grech is now married with two children. He started a legal battle against the Church in 2003 for which he said he would continue to raise awareness. Before the meeting Pope Benedict celebrated a large open-air mass in Valletta, attended by thousands of people. The pope's last event in Malta was a meeting with young people on Valletta's waterfront, where he arrived by boat. He told the youth that today's culture promotes ideas and values that are different from those of Jesus. It is easy when one is young and impressionable, the pope said, to be swayed by peers to accept ideas and values that do not belong to Jesus. Malta's society, the pope said, is steeped in Christian faith and values. "You should be proud that your country both defends the unborn and promotes stable family life by saying no to abortion and divorce," said Pope Benedict. Pope Benedict's visit to Malta was aimed at commemorating the 1,950th anniversary of the shipwreck of Saint Paul on the island.

Italy's foreign minister says Afghan authorities have released three Italian aid workers detained in southern Afghanistan earlier this month.

Foreign Minister Franco Frattini said Sunday he was satisfied with the swift resolution of the case.

Afghan authorities in the southern city of Lashkar Gah arrested the three members of the Italian medical charity Emergency, along with six other employees, on April 10. Authorities had accused the aid workers of involvement in a plot to kill the governor of Helmand province.

Afghan police said weapons and suicide vests were found in the hospital where they worked. The aid workers strongly denied the accusations.

The Italian foreign minister said the release came about without "putting into question" Italy's solidarity with Afghanistan in the international fight against terrorism.

Italy has more than 3,000 troops serving in Afghanistan with the NATO-led international forces.

Meanwhile, NATO says one of its service members has died from a roadside bomb attack in southern Afghanistan. The soldier's nationality was not given in Sunday's statement. NATO previously reported the killing of two Dutch soldiers Saturday by a roadside bomb in Uruzgan province. The Netherlands' Defense Ministry said a third Dutch soldier was seriously wounded in that attack. It is not clear if the latest service member to die was that wounded soldier.

NATO also says Afghan and international forces found two caches of weapons in the Garm Ser and Lashkar Gah districts of Helmand province Saturday. The weapons included assault rifles, explosive devices and materials used in bomb-making.

Another joint patrol found a cache of weapons in Kandahar province after receiving a tip from an Afghan civilian. NATO added Sunday that Afghan and international forces found more than 1,700 kilograms of opium and about 280 kilograms of hashish in two trucks in Helmand province on Saturday.

The joint force took the truck occupants into custody and plans to destroy the narcotics.

Veteran pro-Turkey politician Dervis Eroglu has won the Turkish Cypriot presidential election on the divided island of Cyprus, defeating incumbent Mehmet Ali Talat. Dervis Eroglu of the National Unity Party, took 50.4 percent of the vote, while Mehmet Ali Talat secured only 43 percent. Mr. Eroglu is seen by many voters as a hardliner, who opposes reunification of the Turkish Cypriot northern part of the island with the Greek south, instead calling for a two-state solution. That proposal is long been rejected by Greek Cypriots. President Talat, who favors reunification, has been in office since 2005 and has been holding U.N.-sponsored reunification talks with the Greek Cypriots since September 2008. His defeat has heightened fears that the talks could breakdown. Shortly after he cast his ballot, Mr. Talat said election laws bar him from commenting on the voting results, but he wished all of the candidates good luck. "I wish all the best to everybody, both Turkish Cypriots and Greek Cypriots. I am sure that it will be for the benefit of the whole island. That is my expectation and my wish," he said. After casting his ballot, Mr. Eroglu told reporters that he hoped he would be in a position to continue the Cyprus peace talks. "I am also willing to have a settlement in Cyprus," he said. Turkish Prime Minister Recep Tayyip Erdogan has urged Cypriot leaders to continue peace talks, whatever the results in the election. The continuing division of Cyprus also poses one of the most difficult issues affecting E.U.-Turkey relations, with the future of Turkey's accession hinging on the successful resolution of the Cyprus issue. More than 155,000 voters participated in the election - strong turnout compared to five years ago. Cyprus has been divided since 1974, when Turkey invaded the northern part of the island in response to a military coup that was backed by the Greek government. South Cyprus joined the European Union in 2004 and the self-proclaimed Turkish Republic of Northern Cyprus is recognized only by Turkey.

NATO says one of its service members has died from a roadside bomb attack in southern Afghanistan. The soldier's nationality was not given in Sunday's statement. NATO previously reported the killing of two Dutch soldiers Saturday by a roadside bomb in Uruzgan province. The Netherlands' Defense Ministry said a third Dutch soldier was seriously wounded in that attack. It is not clear if the latest service member to die was that wounded soldier. NATO also says Afghan and international forces found two caches of weapons in the Garm Ser and Laskar Gar districts of Helmand province Saturday. The weapons included assault rifles, explosive devices and materials used in bomb-making. Another joint patrol found a cache of weapons in Kandahar province after receiving a tip from an Afghan civilian. NATO added Sunday that Afghan and international forces found more than 1,700 kilograms of opium and about 280 kilograms of hashish in two trucks in Helmand province on Saturday. The joint force took the truck occupants into custody and plans to destroy the narcotics.

Pakistan police say a suicide car-bomber attack on a police station killed seven people, including a child, and wounded 26 in northwest Pakistan Sunday.

Authorities say at least six police were among the wounded. Police say about 200 kilograms of explosives were used in the attack in the Kohat region. It was the second attack in the region in two days.

Two suicide bombers blew up their explosives at a camp for refugees Saturday, killing at least 41 people and wounding more than 60 others.

Police say the bombers struck minutes apart at the Kacha Pukka camp for displaced people as residents lined up to register for aid.

The Associated Press says the bombers were men disguised in burqas - the full body covering worn by conservative Muslim women.

A retired Pakistani military official told VOA he believes the Taliban is responsible for the attack. Northwest Pakistan has suffered a major internal displacement of people as a result of Taliban violence and a series of military operations targeting Islamist militants near the Afghan border.

The U.S. military says one of its helicopters has crashed in northern Iraq, killing an American soldier and injuring three others.

The military says the cause of the crash late Saturday is under investigation, but is not believed to be linked to enemy fire. An Iraqi military official says the helicopter went down near the city of Tikrit.

In another development, the national airline of the United Arab Emirates, Etihad Airways, plans to begin regular passenger flights to Baghdad on April 26.

The airline said Sunday it will launch five return flights a week from Abu Dhabi to Baghdad using Airbus A320 planes, subject to government and regulatory approval.

The plan would make Etihad the first Emirati airline to provide regular passenger flights to Iraq. Etihad says it hopes to add an additional route between Abu Dhabi and the city of Irbil in Iraq's autonomous Kurdish region starting June 1.

Etihad chief executive James Hogan says the airline expects strong demand on the routes from government and business travelers.

International airlines have been returning slowly to Iraq as its security improves and economic activity picks up following years of conflict.

International Organization for Migration says people in Iraq no longer are fleeing their homes to escape violence. An IOM report indicates tens of thousands of displaced Iraqi families have returned to their places of origin. Four years ago, the bombing of the Al-Askari Mosque in the northern city of Samarra triggered a mass exodus.

The International Organization for Migration says a number of factors contributed to the return home of many displaced Iraqis. Some expressed in the survey that the country felt more secure. Many also said they were persuaded to return home to better living conditions. But, the report finds those returning to their places of origin still face numerous problems.

Jean-Philippe Chauzy, a spokesman for the International Organization for Migration, says one of them is linked to property. "Houses that were left behind might have been destroyed or they could be occupied by other displaced persons," he said. "So, there is a property issue here that needs to be looked at and needs to be addressed. People who are returning home are also facing problems of accessing food, accessing potable water. They are also faced with issues when it comes to accessing quality health care or sending their children to school," added Chauzy.

But Chauzy notes the problems faced by the millions of Iraqis who remain displaced are far worse. Although new displacements have virtually stopped, he says the crisis is far from over.

IOM reports more than 62,000 displaced families or 374,000 individuals have returned to their places of origin since mid-2007. Most have returned to the Baghdad governorate. While this is an impressive number, IOM notes almost 2.8 million Iraqis are still internally displaced. Nearly half of them were displaced before the U.S.-led invasion of Iraq in March 2003.

Chauzy says displaced people cite lack of jobs, decent shelter, access to food, water, health care and legal help as among their most pressing needs. "Shelter, for instance, 58 percent of the people we assessed continue to live in sub-standard rented accommodations. One important point is that actually less than one percent of the displaced we have interviewed live in tented camps," he said. "So, the overwhelming majority of displaced people continue to live either in rented accommodation, in public buildings, in all military camps or in crude squatter settlements, which again, where the living conditions are very, very difficult."

Chauzy says displaced people view tented camps as a last resort. He says they find conditions in these camps so terrible, they will do anything to stay out of them, even if that means living in sub-standard shelters.

The European Union presidency says it hopes some air traffic will resume Monday, easing the near-complete disruption of flights caused by volcanic ash from Iceland. The Spanish secretary of state for EU affairs, Diego Lopez Garrido, says weather forecasters predict skies will clear over parts of Europe Monday, allowing about 50 percent of flights to operate.

But Britain, Germany, and the Netherlands say their airspace will remain closed much of the day. A volcano in southeastern Iceland erupted Wednesday, sending a thick cloud of ash and dust into the air that cancelled most trans-Atlantic and European flights.

Volcanic ash contains glass and rocks that could cause jet engines to shut down in mid- flight. Major European airlines, including KLM, Lufthansa, and Air France, conducted test flights with no passengers Saturday and Sunday and reported no problems.

But meteorologists warned that unpredictable wind shifts were still making air travel too dangerous Sunday. Industry analysts say the airlines are losing about $200 million a day because of the canceled flights, which are also snarling plans for U.S. and Asian travelers.

Air Berlin chief Joachim Hunold criticized the airline shutdowns. He says the decisions were based only on computer models that show how much ash may be in the air.

German media quoted him Sunday as saying that no one has sent up weather balloons to take actual readings.

Witnesses in Somalia's capital say at least eight people have been killed in a land mine explosion.

The blast occurred late Saturday in Mogadishu's Waberi district, near a police station. Witnesses say five members of the security forces were killed, along with at least three civilians.

No one has claimed responsibility for the attack, though friends and relatives of the dead blamed the insurgent group al-Shabab.

Somalia's transitional government is battling Islamist groups who are trying to impose a harsh form of sharia, or Islamic law, on the country.

Earlier on Saturday, the militants fired mortar rounds at the Mogadishu airport, prompting return fire from government troops and African Union peacekeepers.

Reports from the city say at least 10 people were killed, most of them civilians.

The airport is one of the few areas of Mogadishu the government controls. Al-Shabab and another Islamist group, Hizbul Islam, control most of the capital and large parts of southern and central Somalia.

The U.N.-backed government has promised a major offensive against the Islamists for months, but the offensive has yet to materialize.

Somalia has not had a stable central government since 1991.

Some information for this report provided by AP, AFP and Reuters.

Chinese President Hu Jintao has arrived in the earthquake disaster zone in remote western China as the mass cremation of victims begins. The quake toll has risen to more than 1,700 dead.

Chinese President Hu Jintao cut short his trade talks visit to South America to fly into remote Yushu County to inspect the relief effort.

State media said president Hu chaired a meeting of China's top leaders Saturday, urging all-out efforts for the quake response before flying from Beijing.

Officials said despite difficulties, urgent food, shelter and medical supplies were getting through to most survivors.

The Ministry of Civil Affairs' Zou Ming says most victims in the quake hit area now have access to clean water and other basic needs. He says many are now living in tents. Zou says getting aid to the region remained a problem, however.

Hu's visit follows that of Chinese Premier Wen Jiabao, who spurred on the relief effort last Thursday.

Despite early difficulties reaching the worst hit areas on the high altitude Tibetan plateau, including altitude sickness among rescuers, authorities say the relief operation is in full swing. But hundreds in hard-to-reach places remain without desperately needed food and shelter.

Some non-government aid agencies have set up distribution centers outside badly affected Gyegu to avoid looting and fights over food that they say have occurred in the town.

Tibetan Buddhist monks, many of whom have arrived in the area on pickup trucks from other Tibetan regions, have helped remove the bodies of those killed in the earthquake. They say they have cremated more than 1,000 bodies.

Iceland's volcano erupted Wednesday and has since been spewing ash several miles into the air. The ash clouds include particles of rock, glass and sand that can get into an aircraft's engine and cause it to stall.Northern European skies were clear of most commercial planes Saturday. The European air traffic agency said Iceland's volcanic eruption, which began on Wednesday, will continue to impact European aviation until at least Sunday morning. Thick clouds of ash continue to blow across the continent. Hundreds of thousands of passengers around the world remain stranded for a third day as European flights were slashed Saturday down to one-quarter of their normal number. The shutdowns are expected to continue for at least another several days. People have crowded onto trains, buses and ferries in a bid to carry out their travel plans - and cab companies say they are being paid thousands of dollars to ferry people across Europe by car. The European air traffic control agency Eurocontrol said only 6,000 flights would take place in European airspace Saturday - down from the 22,000 normally expected. On Friday, Eurocontrol said about 16,000 or Europe's usual 28,000 daily flights were canceled. Airspace in northern France was closed until Monday morning. Southern Europe, including Spain, southern Italy, Greece, and Turkey remains open for flights. Martin Crozier, senior meteorological officer at the Guernsey Met Office in England, says the volcanic eruption in southeast Iceland that has sent European aviation into meltdown is showing no sign of easing up. "The situation hasn't improved at all I'm afraid," he said. "The volcano over Iceland is still producing quite a lot of ash. The upper level winds are still transporting that down towards the U.K. and northwest Europe. So if anything we have a reinforcement of the ash that's already up there - so things aren't looking too good today I'm afraid."

Crozier says the wind patterns that are pushing the volcanic dust towards Europe are expected to persist for days to come. "I think we're going to get the upper level winds carrying that ash down for a few more days yet until the upper wind patterns change which will probably not happen until the time frame Thursday-Saturday. So really at a worst-case scenario, with the volcano still going strongly, we could get airspace affected for the next few days," he said.

Iceland's volcano erupted Wednesday and has since been spewing ash several miles into the air. The ash clouds include particles of rock, glass and sand that can get into an aircraft's engine and cause it to stall.

The International Air Transport Association said Friday that the airline industry is losing more than $200 million in revenue a day - and they called this a conservative estimate.

Crozier says European aviation has never seen anything like it. "In terms of disruption to aviation I think this is probably the worst it's been in northwest Europe," he said.

The last major disruption to European aviation followed the September 11 attacks in the United States almost a decade ago. U.S. airspace was closed for three days and European airlines cancelled all transatlantic flights.

The World Health Organization has warned people with breathing problems to remain indoors as much as possible when the ash is falling.

Airspace was closed Saturday in at least parts of more than a dozen countries - in some countries, the skies were emptied of commercial flights.