A grenade has exploded among protestors outside government house in Bangkok, wounding 34 people.
The grenade landed near the prime minister’s offices, which have been occupied by the People’s Alliance for Democracy since August.
Earlier, anti-government demonstrators hurled iron rods and firecrackers at police lines near the airport, forcing riot police to flee.
Officers abandoned another checkpoint near the airport under pressure from protesters, although then events passed off peacefully.
The US and EU have called for members of the People’s Alliance for Democracy to abandon both Bangkok airports they are occupying, without delay.
Thai tourist authorities are block-booking hotels to accommodate stranded passengers.
Tens of thousands of people are desperately trying to find a way out of the country.
Thailand’s deputy prime minister said today that repatriating foreign holidaymakers could take up to a month. And he warned of the long term damage to Thailand’s tourist image.