At least one Thai anti-government protester was killed and 21 were wounded in a pre-dawn bomb blast Thursday inside a demonstration site in Bangkok, emergency services said.

The bomb went off at 3:28 am (2028 GMT) in front of a stage at the Government House compound, which protesters from the so-called People`s Alliance for Democracy (PAD) occupied in late August.

Twenty-two demonstrators wounded by the bomb blast were taken to four nearby hospitals, emergency services said. One later died and 10 were still in a serious condition, they said.