The demonstrators, from the right-wing People's Alliance for Democracy, stopped once they entered the compound at Government House at about 2:30 p.m. and did not attempt to enter the official offices there, footage on Thai TV channel 9 showed.

Earlier, mobs of alliance protesters took over a state-controlled television station and besieged several ministries in a self-described "final showdown" to try to bring down the elected government of Prime Minister Samak Sundaravej.

It was the first time in recent years that a large crowd managed to get onto the Government House grounds. The crowd of several thousand appeared peaceful.

Samak was expected to speak about the situation late Tuesday afternoon.

The protests were the latest effort by the alliance to force Samak's government from office. The group contends Samak is a proxy for former Prime Minister Thaksin Shinawatra, who was ousted in a 2006 coup and now has gone into self-imposed exile in England.