Deputy police spokesman Pol Maj Gen Surapol Tuanthong told reporters, "The protesters must leave the government compound before 6:00pm, otherwise they will be asked to leave."
"They have caused disorder and breached the law."
The order came after Police chief Pol Gen Patcharawat Wongsuwan held talks with Deputy Prime Minister Pol Gen Kowit Wattana.
Prime Minister Samak Sundaravej has assigned Kowit to handle the protests which was led by People's Alliance for Democracy. The protests seized many government agencies including the Government House.