Thailand remains tense as troops act to remove anti-government protesters in Bangkok. As the violence mounts in the heart of the capital, many regret the failure of a plan that offered a way for the government and protesters to peacefully resolve their differences.

The gunfire and explosions that reverberated in central Bangkok Friday put to death the hopes created last week. That was when Prime Minister Abhisit Vejajjiva offered a reconciliation plan, which, combined with behind-the-scenes negotiations, seemed to end the threat of new violence between government forces and the red-shirt protesters.

The anti-government rallies at the Rajaprasong commercial area in Bangkok since early April have paralyzed business with massive revenue losses. The government has been under increasing pressure to end them. But the protesters, known as red shirts, refused to leave until Mr. Abhisit called immediate elections.

However, the red-shirt leaders unexpectedly welcomed the prime minister's reconciliation plan, which included elections in November. The city seemed to breathe a sigh of relief.

Kraisak Choonhavan, a key member of the governing Democrat Party, said the plan's hopes rested on it being accepted by red shirt leaders, and Mr. Abhisit's willingness to compromise.

"He's willing to compromise to a great extent and that's what he's done," he said. "The shortcomings of the result of the negotiations was quite startling to all of us because they [red-shirt] leaders had set a date for the dismantling of the barricades and move out, the cessation of all violence."

But the red shirts set down additional demands, particularly over the investigation of clashes with security forces on April 10. Their demands eroded faith in reconciliation plan.

No amnesty for Thaksin

And some political analysts here say the two sides failed to agree on an amnesty for Thaksin Shinawatra. The former prime minister, a major supporter of the red shirts, was ousted in a military coup in 2006, and now lives overseas to avoid a prison term for corruption.

On Thursday, the government began to isolate the protest camp, throwing up a tight security cordon around the camp, cutting off telecommunications, and blocking supplies of food and water. That sparked a series of clashes on the streets through the night, and that were continuing Friday night. Scores have been wounded.

Sunai Pasuk, a representative in Thailand for Human Rights Watch, fears the military's strategy could make matters worse.

"To me, in a situation like this and with protesters who are very defiant and agitated, this is an ingredient for disaster," he said. "This is a very dangerous situation that the government needs to operate with extreme care about the rules of [military] engagement. So I am very concerned."

But Sunai says the situation is complicated because moderate red-shirt leaders are reported to have left the movement. Those remaining have advocated more violence to force the government out.

Thitinan Pongsudhirak, a political science professor at Chulalongkorn University, says many red shirts remain angry over court decisions that tossed out two elected pro-Thaksin governments in 2008. Their removal opened the way for parliament to make Mr. Abhisit prime minister.

"When you deny, when a substantial number of voters are denied and disenfranchised they will become disillusioned and take action upon themselves," he said.

As a result, Thailand faces its most political violence in almost 20 years, as the military seeks to retake key locations while the red shirts remain defiant - and willing to fight to the end.