There has been more deadly violence in Bangkok.
At least one anti-government activist has been killed.
A rogue general, backing the red shirt protest movement, has been shot in the head and seriously injured. Khattiya Sawasdipol is said to advise demonstrators on their military tactics.
Shortly after he was rushed to intensive care, the United States closed its embassy in Bangkok, and Britain said it was doing the same.
Explosions and gunfire were heard as the Thai army moved to lockdown a fortified encampment occupied by thousands of protesters.
Demanding the immediate dissolution of parliament and new elections, they have ignored a government ultimatum to leave.
Prime Minister Abhisit Vejjajiva is under huge pressure to end the two month standoff that has killed at least 30 people and wounded more than 1,000.