BANGKOK - THAI Prime Minister Samak Sundaravej has ordered 'thousands' of riot police to move the royalist crowd occupying his Government House by Wednesday, his spokesman said.

'The Prime Minister said it has to end today,' Mr Samak?s chief spokesman Wichianchot Sukchotrat told reporters. 'Thousands of police will be deployed to move the protesters out of the Government House.' Earlier on Wednesday, Thailand issued arrest warrants for protest leaders besieging the main government complex, as authorities scrambled to find a peaceful end to the administration's most serious challenge yet.

As riot police moved in, leaders of the People's Alliance for Democracy (PAD) vowed to stay inside the Government House compound until Prime Minister Samak Sundaravej bows to their demands to step down.

'The Criminal Court has approved arrest warrants for nine people as proposed by the police, including five PAD leaders,' a court official said.

'They face four charges - the most severe is treason,' he told AFP.

On Tuesday, up to 35,000 demonstrators stormed a state-run television station, besieged at least three ministries and finally invaded the grounds of Government House, stepping up a campaign to bring down Mr Samak's administration.

Police have indicated that they will enter the compound to arrest the PAD members, but Interior Minister Kowit Wattana appeared to he holding out for a peacefully solution.

'I ask protesters of the PAD to please withdraw from the Government House compound immediately. You can rally somewhere else,' he told reporters.

But despite government pleas, the threat of arrest, and even the onset of a tropical rain storm, protest leaders refused to budge.

'If you want to arrest us, come here and arrest us here - it is the government who must go,' Somsak Kosaisuk told protesters, most of whom were wearing yellow shirts out of allegiance to revered King Bhumibol Adulyadej.

Small scuffles broke out between police and protesters early on Wednesday, deputy national police spokesman Major General Surapol Tuanthong said, but he insisted there would be no violence.

'They are not going to disperse the crowd - we are trying to negotiate,' Maj Surapol told AFP, adding that about 14,000 protesters remained inside the compound.

An AFP correspondent at the scene saw hundreds of police, some with batons and shields, in the enclosure. The security forces appeared relaxed, watching the ongoing rally on the manicured lawns of Government House.

One police officer who refused to be named said that 2,000 police were deployed outside Government House, while 500 were inside.

The PAD movement, which has been protesting since May, says that Samak is a proxy running the country on behalf of former premier Thaksin Shinawatra, who was ousted in a 2006 coup and is barred from holding office. -- AFP/REUTERS