BANGKOK, Nov. 30 (Xinhua) -- The injuries from the explosion at the anti-government rally site of the People's Alliance for Democracy (PAD) in Bangkok's Government House early Sunday injured 50 protesters, according to the PAD.

    The PAD announced that a total of 50 protesters were injured inthe grenade explosion inside the Government House in central Bangkok early Sunday.

    Kittichai Saisa-ard, chief of PAD guards, was quoted by The Nation news website as saying that 47 protesters were sent to the Ramathibodi Hospital, four of them severely injured. He said two other protesters were sent to Phra Mongkut Hospital and another toVajira Hospital.

Anti-government protesters sit near a bus used as a barricade outside the Government House in Bangkok Nov. 30, 2008. The injuries from the explosion at the anti-government rally site of the People's Alliance for Democracy (PAD) in Bangkok's Government House early Sunday injured 50 protesters. (Xinhua/Reuters Photo) Photo Gallery>>>

    News reports said the grenade landed near the prime minister's offices, which have been occupied by protesters led by the PAD since August.

    The blast occurred near Government House where thousands of PADsupporters, who are demanding Prime Minister Somchai Wongsawat to step down, were holding a rally.

    PAD leader Suriyasai Katasila told Channel 3 that he had come down from the stage about 30 minutes before the grenade dropped into a crowded area. The injured protesters were rushed to nearby hospitals, TV reports said.

    He accused pro-government supporters of launching the attack. The explosion came hours after anti-government demonstrators forced police to abandon a checkpoint at the main Suvarnabhumi airport.

    In the latest clash with protesters, about 150 riot police had to retreat from their checkpoint near Suvarnabhumi International Airport on Saturday night after being attacked by PAD supports armed with iron rods.

People's Alliance for Democracy (PAD) security personnel inspects the site of a blast inside the Government House in Bangkok Nov. 30, 2008. (Xinhua/Reuters Photo) Photo Gallery>>>

    The PAD is seeking to topple the government, which they accuse of being a proxy of the ousted Prime Minister Thaksin Shinawatra.

    After the PAD protesters seized the Suvarnabhumi and Don Mueangairports, the government declared a state of emergency at the airports on Friday.

    Prime Minister Somchai is now in the northern province Chiang Mai, where he made a temporary government seat after returning from an APEC meeting. Deputy Government Spokeswoman Suparat Nakboonnam earlier said that Somchai has no schedule to return to Bangkok in the near future.

    She said Somchai decided to remain in Chiang Mai for security concern due to uncertainties related to the moves of the armed forces, and his moves would be kept secret.

    In a related development, Thailand is considering to postpone the Association of Southeast Asian Nations (ASEAN) summit due to the political turmoil in the country, according to Thai Foreign Minister Sompong Amornwiwat.

    Leaders of 10 ASEAN countries plus those of China, Japan and South Korea, are scheduled to meet in Chiang Mai between Dec. 14-18.

    The summit was initially planned to be held in Bangkok, but the government decided to move to Chiang Mai because of the demonstration.