Two Bangkok airports suffered two explosions wounding four people early Wednesday, triggering the closure of the main international airport.

The explosions happened a day after thousands of anti-government protesters rallied on the airports to protest the return of Thai Prime Minister Somchai Wongsawat from the APEC summit in Peru.

An airport official said one blast occurred at Suvarnabhumi Airport at 5 a.m. (2200 Tuesday GMT). A civilian was wounded in that attack.

The other blast occurred at 6:40 a.m. Wednesday (2340 Tuesday GMT) at the Don Muang International Airport, hurting three people, the police said.

According to Assistant Airport Director Serirat Prasutanond , continued protests has led authorities to cancel all incoming and outgoing flights. Three protesters also managed to enter the airport's control tower, trying to get the prime minister's flight schedule.

Suvarnabhumi Airport later canceled all flights.