Thai riot police have surrounded the prime minister's compound to try to evict anti-government protesters who took over the building on Tuesday.

But demonstrators are vowing to stay camped in the grounds of the premises until PM Samak Sundaravej steps down.

A court has issued arrest warrants for nine protest leaders on charges of trying to overthrow the government.

The protesters say Mr Samak is a proxy for former PM Thaksin Shinawatra, who was ousted in a military coup in 2006.