BANGKOK - THAI anti-government protesters left home-made bombs and molotov cocktails at the prime minister's office in Bangkok at the end of a three-month siege of the complex, police said on Thursday.

Officials also said three cars and jewellery had disappeared from Government House during the occupation by the People's Alliance for Democracy, although one anonymous donor paid off a big water bill.

PAD demonstrators took over the complex in late August and vacated it on Monday to reinforce a blockade of Bangkok's airports. They ended all protests after a court ousted Prime Minister Somchai Wongsawat on Tuesday.

'Police found a number of molotov cocktails, homemade bombs, clubs and machetes around Government House this morning,' Major General Anan Srihiran, of Bangkok Metropolitan police, said.

'There are more than 100 items, we will keep them as evidence,' he said.

The protesters had caused 25 million baht (S$1.09 million) of damage and run up an electricity bill of 900,000 baht during their time there, said Mr Nathi Premrasmi, permanent secretary for Government House.

'Three cars have also disappeared and more than 10 cars belonging to the National Security Council have been damaged... jewellery has been taken,' Mr Nathi said.

An unidentified person had donated 200,000 baht to cover a water bill, Mr Nathi added.

Government officials were not being allowed inside the building until special branch police had cleared all the weaponry.

About 17,000 protesters filled the Government House complex at the peak of the demonstration, accusing the government of corruption and acting on behalf of ousted premier Thaksin Shinawatra, and demanding it step down.

Protesters had been camped out for more than three months, filling the ornate lawns and surrounding the main Venetian-style building, built in 1908 to welcome kings and visiting dignitaries.

The enormous complex normally houses the prime minister's office along with Thailand's National Security Council, the Consumer Protection Board, the government's legal advisers and even a mini-mart.

Meanwhile Mr Nathi said the government would not withdraw criminal charges of trespass against protest leaders.

'(We) cannot withdraw charges against PAD leaders... as requested by their lawyer,' he said. -- AFP