Thai security forces and anti-government protesters are engaging in another violent clash in Bangkok's main commercial district, where fighting in recent days has left two people dead and dozens of others wounded.

Loud explosions erupted from the so-called "Red Shirt" protest zone as security forces fired tear gas and live and rubber bullets into the crowd of demonstrators early Friday. Witnesses say some protesters set fire to an empty police bus before fleeing the scene.

Gunshots were heard in the area throughout the night and into the morning, and one building was battered by shells. Businesses and several foreign embassies located in the upscale district have been closed and evacuated. Mass transit systems have been disrupted as services and stations within the affected zone have been shut down. And the government has extended an emergency decree to 15 other provinces in a bid to prevent more protesters traveling to the capital.

Friday's violence was triggered when a dissident general aligned with the Red Shirts was shot in the head and seriously wounded Thursday as security forces began a crackdown on the protesters' encampment. The wounded general, Khattiya Sawasdiphol, better known as "Seh Daeng" or Commander Red, was struck in the temple while being interviewed by a reporter.

He is in a coma at a Bangkok hospital, and its director says it is doubtful he will survive.

Thai security forces have deployed up to 30,000 troops backed by armored personnel carriers as part of an operation to disperse protesters rallying in central Bangkok for the past two months.The unrest which began in early April in Bangkok's Rajprasong commercial and retail area have forced the closure of hundreds of shops, leading to millions of dollars in revenues losses and thousands of jobs at stake.

On Silom Road, largely empty to traffic and closed off in sections, troops were on standby. Ms. Fah, a resident of Silom, backs the presence of the armed forces. Ms. Fah says the Thai people love their soldiers and are happy to have troops in the area, as well as loving the country's monarch.

Key Red Shirt leaders said Friday they would press on with the rally in defiance of a crackdown and are calling for supporters to gather at another venue in Bangkok. That venue, at Rajadamneon Avenue, was the scene of clashes in April between protesters and security forces that left more than 20 people dead and more than 850 others injured.

But divisions have been reported within the Red Shirt leadership, with some core leaders looking to end the rally after initially welcoming a reconciliation plan offering new elections in November. Prime Minister Abhisit Vejjajiva is said to have withdrawn the early election date.

Many protesters support former Prime Minister Thaksin Shinawatra, ousted in a coup in 2006. Mr. Thaksin was accused by the urban middle class of corruption and abuse of power. But the former leader, who lives outside the country, still commands support among the urban and rural poor through previous populist policies while in power.