BANGKOK - A BOMB blast wounded a Thai anti-government protester on Saturday inside the government compound that an opposition movement has occupied for months, a spokesman for the group said.

People's Alliance for Democracy spokesman Parnthep Wongpuapan said he wasn't sure how the bomb was planted inside Government House grounds in the capital, Bangkok. He blamed unspecified enemies of the protest movement, which has vowed to topple Thailand's elected government.

The protesters did not report the blast to police, though officers were aware it had happened, police Sgt Nareukrai Buran said.

Mr Parnthep said the demonstrators did not report the bomb because they didn't want police to enter the compound to investigate. He said the blast occurred around dawn and the injured protester was in serious condition, but gave no details.

The PAD - a loose alliance of royalists, business owners, students and activists - has illegally occupied Government House, which houses the prime minister's office, since Aug.

They demand that the government resign, saying it is a proxy for former Prime Minister Thaksin Shinawatra, who was ousted in a 2006 military coup for alleged corruption.

Thaksin's allies won elections in Dec, but the government they formed has run into trouble almost from the beginning.

Current Prime Minister Somchai Wongsawat, who is Thaksin's brother-in-law, has been forced to operate out of a makeshift office at Bangkok's old international airport.

Thaksin was convicted on Oct 21 of violating a conflict-of-interest law in a case relating to a real estate deal by his wife, who was acquitted. He was sentenced in absentia to two years in prison, but earlier fled to Britain, saying he could not get a fair trial in Thailand.

Thai newspapers reported on Saturday that Britain has revoked Thaksin's visa. A British embassy official said he could not comment on individual immigration cases. -- AP