Anti-government protesters in Thailand blockaded the country's main international airport late Tuesday halting departing flights amid signs of increasing tensions between pro- and anti-government demonstrators. As Ron Corben reports from Bangkok the violence and civil disobedience has escalated as protesters try to force the ouster of Prime Minister Somchai Wongsawat's government.

Hundreds of anti-government protesters led by the People's Alliance for Democracy or PAD swarmed into Bangkok's main international air terminal building Tuesday evening.

Earlier, demonstrators had cut off the main access route to the airport, the vital gateway for millions of passengers each year. The PAD this week has stepped up its efforts to force Prime Minister Somchai Wongsawat's government from office.

The airport siege also followed a clash between pro- and anti-government PAD protestors. Several shots were fired and at least 10 people were injured in the brief melee.

The violence was captured on Thai Public Service television. The footage also showed PAD supporters using knives with three motorbikes set on fire. Pro-government supporters, wearing red shirts and head scarves had been seen earlier with long metal pipes.

Chris Baker, an author and commentator on Thai politics, described the situation as disturbing. Baker was also critical of the PAD's tactics.

"I think this is the death throes of the PAD rather than anything that is going to go anywhere," said baker.  "The effort at the airport is stupid. And of course its hugely damaging; this is enormous damage to Thailand just this blockading of the airport."

The rallies, seen as a final push by the anti-government People's Alliance for Democracy, forced parliament to delay its session Monday by blocking access to the building.

The PAD accuses Mr. Somchai of trying to pass constitutional amendments to halt corruption cases against his brother-in-law, former Prime Minister Thaksin Shinawatra.

But Mr. Somchai, who has been in Peru for a meeting of Asia Pacific leaders, dismisses the accusation. He criticizes the PAD for leading a rebellion.

Public support for the PAD appears to waning. It has occupied a government administration building since late August and its leaders say they want to prevent the cabinet and parliament from conducting any business.

Security forces have so far avoided any direct confrontation with the  PAD protests. Authorities seek to avoid a repeat of a clash last month in which two people died and about 400 wounded.