BANGKOK (Reuters) - Pressure built on Thailand's military to intervene in a political crisis threatening to descend into widespread civil unrest on Thursday after Prime Minister Somchai Wongsawat rejected calls to quit.
Speaking on national television, Somchai said his government was democratically elected and would continue to work for the "good of the country" despite claims by the People's Alliance for Democracy (PAD) it is the puppet of ousted Prime Minister Thaksin Shinawatra.
His refusal to call a snap election, as army chief Anupong Paochinda said he should at an earlier news conference on Wednesday, intensified speculation of an imminent coup, despite Anupong's stated aversion to such a move.
One military source said army, navy and air force top brass were locked in talks late into the night debating whether to launch a coup only two years after the removal of Thaksin.
Anupong has repeatedly said he will not take over, arguing the army is powerless to heal the fundamental political rifts between the Bangkok elite and middle classes who despise Thaksin, and the rural and urban poor who love him.
Somchai -- Thaksin's brother-in-law -- returned to Thailand from an Asia-Pacific summit in Peru to find Bangkok's international airport shut down by a PAD siege and tension rising across the country.
In the northern city of Chiang Mai, a pro-government gang shot dead an anti-government activist after dragging him from his car, the first serious violence outside the capital, police said.
Anupong also told the PAD street movement to end its crippling siege of Bangkok's Suvarnabhumi airport, where all flights are canceled, leaving thousands of tourists stranded.
A court also issued an injunction telling the group to leave the airport, one of Asia's largest, although the PAD immediately said they would appeal against the order.
PAD spokesman Suriyasai Katasila also rejected Anupong's plan. "We won't pull out, we won't leave if Somchai does not quit," he told reporters.
Domestic flights out of Bangkok's old Don Muang airport were also grounded, all but severing air links with the outside world.
"WAR FOR SURE"
After masked PAD members stepped up their action by breaking into the control tower at Suvarnabhumi, a rival pro-government group said it would launch its own street action, raising the prospect of clashes.
"What they have done are terrorist acts," Jatuporn Prompan, a ruling party politician and leader of the anti-PAD Democratic Alliance Against Dictatorship (DAAD), told a news conference.
One senior DAAD source said the movement would consider any retreat by the government to be a military coup, and immediately launch a counter street offensive against the army.
"There will be war for sure," the source told Reuters.
Somchai is due to hold a cabinet meeting in Chiang Mai on Thursday at which he would consider "measures" against the PAD, although he provided no specifics.
Although the PAD has been campaigning non-stop for six months, it engineered a "final battle" on Monday, telling supporters the government would get parliament to amend the constitution to favor Thaksin, who has been convicted of graft and is now in exile.