Anti-government protesters who have closed down Bangkok's airports broke through a police cordon meant to shut them off from supplies, raising fears Saturday of widening confrontations in the standoff that has strangled the country's economy.

Bangkok's domestic airport has also been seized, severing the capital from all commercial air traffic and virtually paralyzing the government.

The closure of the airports has taken a heavy toll on Thailand's economy and reputation. According to Thai media reports, some 100,000 tourists are stranded, and schedules of airlines around the world have been disrupted.

So far security forces have only issued a warning to the protesters to leave. It was not clear if the assault will result in a changed strategy.

Click here for photos.

Earlier Saturday, Police spokesman Maj. Gen. Amnuay Nimmano said the protesters would be told to leave the airports. If they did not, a deadline will be issued with another warning, "the last one before we take action," he said.

The protesters, who call themselves the People's Alliance for Democracy, accuse the government of being a puppet of former Prime Minister Thaksin Shinawatra, who was ousted by a 2006 military coup and fled overseas to escape corruption charges.

The airport authority said Suvarnabhumi international airport will remain closed at least until Monday evening. The Federation of Thai Industries estimates the standoff is costing the country $57 million to $85 million a day.

Several airlines have begun flying rescue flights to the U-Tapao naval airport, 90 miles south of Bangkok, to evacuate stranded passengers. But the small airport is overwhelmed by the load, unable to process thousands of travelers quickly.

Among those stranded are about 3,000 Chinese tourists who will be flown out on special flights by four Chinese airlines beginning Saturday, China's official Xinhua News Agency reported. It said the Hong Kong government has also arranged two Cathay Pacific flights to help stranded passengers.

Thailand's central bank said the number of tourist arrivals is likely to fall by 40 percent next year if the airport shutdown drags on until the end of December. It said the tourism industry, a key component of the Thai economy, is expected to lose $4.28 billion, equal to 1.5 percent of the gross domestic product.

With international repercussions obvious, the European Union and the United States urged the protesters to end their siege.