Thailand's main international airport in Bangkok is closed on Tuesday for a second day by anti-government protesters.
Thousands of supporters of the People's Alliance for Democracy breached police lines and stormed Suvarnabhumi Airport in their campaign to pressure the premier to resign.
Suvarnabhumi is a Southeast Asian hub for millions of travellers and tourists. Flights will be diverted to the northern city of Chiang Mai or the southern island of Phuket.
Thousands of tourists are reportedly stranded and say no one has told them what they should do.
Earlier, PAD protestors forced the cancellation of a parliamentary joint sitting on Monday.
The PAD is a loose coalition comprising royalists, Bangkok's old elite and the middle class.
It accuses the government, which was elected in December, of being a corrupt puppet of exiled former premier Thaksin Shinawatra. Thaksin was ousted in a 2006 coup after huge street protests by the PAD.