Protesters in Thailand claim they are planning their biggest demonstration yet, as a state of emergency remains in place in Bangkok.

The "red shirts" - who support the ousted Prime Minister Thaksin Shinawatra - are campaigning for snap elections to be called.

Thailand's current premier Abhisit Vejjajiva declared a state of emergency in his country's capital after crowds stormed parliament, forcing government officials to flee by helicopter.

The move gives the army broad powers, lets the authorities suspend certain civil liberties, bans public gatherings of more than five people and stops media reporting news that "causes panic".

The protesters have now retreated from parliament, but tens of thousands have remained in Bangkok's main shopping district since Saturday, defying orders to leave.

They are understood to be planning a major demonstration on Friday but the authorities plan to set up military checkpoints oustside Bangkok to stop anyone from entering the city.