Bangkok  - Protest leaders holding Bangkok's two airports hostage in their bid to topple the government sent mixed signals on Saturday to authorities preparing to crack down on the demonstrators.

Prime Minister Somchai Wongsawat on Thursday declared both Suvarnabhumi International Airport and Don Mueang, Bangkok's former international airport, under emergency decree and ordered the police, air force and navy to clear out thousands of followers of the People's Alliance for Democracy (PAD), a movement that has been staging increasingly violent protests for the past six months.

PAD leader Sondhi Limthongkul on Saturday vowed to "fight to the death" if police attempt to seize him at his ASTV headquarters in Bangkok, but another core leader, Chamlong Srimuang, claimed he was ready to open talks with the prime minister.

The two leaders have proven master strategists over the months of directing anti-government protests that have succeeded in occupying Government House - the seat of the administration - and now the capital's two airports in their efforts to bring the government down.

The airport takeovers this week may have shifted public opinion against the movement. Suvarabhumi has been closed to air traffic since Wednesday and Don Mueang since Thursday.

The PAD has drawn a diverse base of backers from Bangkok's middle class, provincial people opposed to corruption and the country's political elite.

The police have been reluctant to attack the demonstrators, who include many middle-aged women, families with young children, veteran political agitators and hardcore, golf club-wielding guards.

By mid-day Saturday, police had gathered several kilometres away from the two airports, but had refrained from attacking.

The last time police cracked down on the PAD, at a demonstration outside Parliament on October 7, two protestors were killed when tear-gas cannisters were fired into the crowds.

The police came under public criticism for the action, and Queen Sirikit, the wife of Thailand's revered King Bhumibol Adulyadej, attended the funeral of one of the victims.

The airport closures have stranded an estimated 100,000 passengers who want to leave the kingdom, according to Tourism Minister Weerasak Kowsurat. Industry sources said they are losing 3 billion baht (86 million dollars) a day in unshipped cargo.

Governments around the world have warned their citizens against travel to Thailand, hitting the country's tourism sector, which has already been hurt by the global financial crisis. The US government on Friday criticized the PAD's seizure of the airports as "not an appropriate means of protest."

The airport crisis has demonstrated the weakness of the current government. Somchai has essentially moved his cabinet to Chiang Mai, 550 kilometres north of Bangkok, for fear of a coup.

Somchai is the brother-in-law of Thaksin Shinawatra, a former prime minister who was ousted by a bloodless military coup in September 2006 and is now living in self-imposed exile, a fugitive from the law after being convicted and sentenced to two years in prison for abuse of power.

However, Thaksin remains a key character in Thailand's unfolding political drama.

Using his blog, Thaksin has called on the PAD to cease its protests and the police and military to enforce the law, ironically, since he is fleeing a court sentence himself.

Many political observers believe the growing political chaos is setting the stage for Thaksin's political comeback.

The PAD's main mission is to block his return to power, and the kind of money-politics he represented.

The group is known to be seeking a military coup to launch their proposed "new politics," which would favour appointee governments over elected ones.

But if the military stages a croup this time, it would face immediate opposition from the "Red Shirts," a pro-government group that has rivalled the PAD in leading civil unrest.

"They will fight back right after the coup, starting in Bangkok, so they will have to kill a lot of people," said Chaturon Chaisaeng, the former leader of Thaksin's now defunct Thai Rak Thai party who has close ties with the current government.

Although the military's last coup toppled Thaksin from power in a bloodless putsch, it ultimately failed to stop his followers from returning to power in the December 2007 general elections.

The current government is led by the People Power Party, which came to power on a pro-Thaksin platform. (dpa)