Thailand's army chief told the elected government on Wednesday to step down and call a snap election as a way out of a deepening political crisis.
At a news conference in Bangkok, Anupong Paochinda also told the People's Alliance for Democracy (PAD) protest movement to withdraw from Bangkok's international airport and cease its anti-government campaign.
But anti-government protesters Wednesday said new elections would not solve Thailand's bitter political crisis and refused to end their occupation of Bangkok's main airport.
Thai protesters have tightened their hold on the airport, where two people were wounded in a blast and thousands of travellers left stranded by demonstrators vowing to topple the government.
Two grenade attacks elsewhere in the capital deepened the sense of lawlessness after demonstrators stormed the airport Tuesday night, dramatically stepping up their campaign against Prime Minister Somchai Wongsawat.
Suvarnabhumi Airport, a three-billion-dollar showpiece hub for travel throughout Southeast Asia, was closed down as guards from the PAD protest movement sealed off roads to the facility.
The PAD said it completely controlled the airport -- a pet project of ousted former premier Thaksin Shinawatra that opened with great fanfare in 2006 -- and told airlines to apply directly to the group for landing rights.
"I have been informed by Thai Airways that 3,000 passengers are stranded at the terminal now," airport director Saereerat Prasutanont told AFP, adding that 78 outbound and incoming flights were affected.
"Protesters refused to negotiate with anyone except the prime minister."
Police said at least 8,000 demonstrators, wearing yellow clothes in a traditional symbol of loyalty to the revered monarchy, cheered on PAD leaders who gave speeches from a stage set up in the taxi drop-off area.
"It's not fair," said Vanessa Sloan, 31, from Florida, who was supposed to fly to the northern city of Chiang Mai on Wednesday.
"We spent the night here after all the check-in staff ran away. No one is here to help."
Dejected passengers surrounded by trolleys piled high with baggage were camping out near the check-in desks in the terminal, an AFP correspondent said.
The Australian government warned its citizens Wednesday to take extra precautions if planning to visit Thailand, while Singapore Airlines said it had cancelled its flights to and from Bangkok.
The PAD -- a loose coalition comprising royalists, Bangkok's old elite and the middle class -- is spreading chaos ahead of the prime minister's return from a foreign trip on Wednesday evening.
The alliance launched their campaign in May, accusing Somchai's government of being a corrupt puppet of his brother in law, former PM Thaksin, who was toppled in a 2006 coup and remains in exile to avoid corruption charges.
Senior PAD leader Chaiwat Sinswuwong said the movement had "completely taken control" of the airport.
"So any airline that wants to take off or land must seek permission from us directly," Chaiwat said.
The protesters had only allowed one flight to take off, a departure to Saudi Arabia for the Muslim hajj pilgrimage.