A grenade blast has wounded 34 anti-government protestors at Government House in Bangkok.
It is believed the grenade landed near the prime minister's offices, which have been occupied by the People's Alliance for Democracy (PAD) since August.
Meanwhile, stranded Irish citizens in Thailand will get extra help leaving the country with the arrival of a diplomat from the Irish embassy in Kuala Lumpur.
The Department of Foreign Affairs sent the diplomat to Bangkok to provide Consular assistance and monitor the situation in the city.
Bangkok's main airport will remain closed until Monday following clashes between Thai police and around 2,000 anti-government protesters.
The group organising the protests said its members will not leave the airport until the Prime Minister resigns.
The Thai Prime Minister has promised to use peaceful means to end blockades.
In a televised address, Mr Somchai Wongsawat said the stand-offs with anti-government demonstrators would be resolved by negotiation, but he did not say when.
The protests at the domestic and international airports have cut the Thai capital's links to the world, leaving thousands stranded and hurting the tourist-dependent economy.
Thailand's three-year-old political crisis has deepened dramatically since the PAD began a 'final battle' on Monday to unseat a government it accuses of being a pawn of former leader Thaksin Shinawatra, ousted in a 2006 coup.
Mr Somchai is Mr Thaksin's brother-in-law.
