Anti-government rallies have been held in Bangkok for months
A grenade blast has wounded eight anti-government protesters camped outside the Thai prime minister's office in Bangkok, emergency services say.
Demonstrators from the People's Alliance for Democracy (PAD) group have occupied the area since August.
The attack comes two days after another grenade attack on the protesters killed one person and injured more than 20.
The PAD wants the government to resign, saying it is too close to ousted former PM Thaksin Shinawatra.
The grenade exploded just after 0200 on Saturday (1900 GMT on Friday), and hit a checkpoint staffed by volunteer guards from the PAD, police said.
The protesters have been targeted by small bomb attacks in recent weeks.
Street violence
The PAD is an alliance of conservative and royalist activists.
They accuse Prime Minister Somchai Wongsawat and his recently ousted predecessor, Samak Sundaravej, of being proxies for Mr Thaksin.
The former prime minister, who is Mr Somchai's brother-in-law, was forced from office in a military coup in 2006 and remains in exile.
The PAD wants to replace Thailand's one-man, one-vote system with one in which some representatives are chosen by professions and social groups.
The protests have seen some of the worst street violence since pro-democracy activists challenged Thailand's army in 1992.
People's Alliance for Democracy (PAD) protesters camped in the grounds of Government House 
Early this morning, a grenade attack on People's Alliance for Democracy (PAD) protesters at Thailand's Government House injured eight, two seriously.

This is the second attack this week, following an earlier grenade attack on Thursday which killed one and injured between 20 and 29. The earlier attack prompted planning for a rally and march on parliament tomorrow where the PAD aims to try and topple the current People's Power Party (PPP) government.

According to Thailand's English-language paper, ''The Nation'', doctors have stated that one of those injured in the blast is brain dead. Anupong Samerphak, one of the PAD security staff, was hit in the body and neck by shrapnel from the grenade and remains on a respirator.

Further details of ''The Nation's'' report state that eyewitnesses claim two teenagers made use of a grenade launcher to carry out the attack before making their escape on a motorcycle. In addition to the eight casualties, two pick-up trucks, a car, and a motorcycle were damaged; the blast left a crater near the Fifth gate of the Government House compound.

The anti-government PAD protesters have now been occupying the Government House compound for over three months, demanding the dissolution of the government of Prime Minister Somchai Wongsawat. They assert that the PPP is acting on behalf of deposed former premier Thaksin Shinawatra, whose populist Thai Rak Thai (lit. Thais love Thais) government was overthrown by a military coup in 2006 and later outlawed. Both Somchai and his predecessor in the post of PM, Samak Sundaravej, have faced fierce criticism from the yellow-shirted protest movement. Samak was forced out of office in September, with Somchai, Thaksin's brother-in-law, acting as caretaker until officially assuming the office later in September.

The embattled current PM, Somchai, expressed fears to journalists over the planned PAD protest for tomorrow and Monday. Speaking in Peru, where he is attending an APEC summit, he highlighted the possibility of the demonstrations impeding the passage of 24 new laws related to the country's involvement in the Association of Southeast Asian Nations (ASEAN). Delegations from other nations attending the APEC summit have expressed surprise that Thailand has not taken action to dislodge the protesters from Government House.