A core leader of the anti-government red-shirts movement on Saturday vowed to prevent Prime Minister Abhisit Vejjajiva from returning home and returning to work at the Government House.

Some 500 motorcyclists would be deployed to hound Abhisit to prevent him from returning home in Bangkok, The Nation online quoted Arisman Pongruangrong, a hardliner of the United Front of Democracy against Dictatorship (UDD) who led protesters to storm and force last April's ASEAN Summit, as saying.

Meanwhile, Jatuporn Promphan, a UDD core leader said that he would lead protesters to besiege the Bangkok Metropolitan Administration's headquarters.

"The demonstrators were dissatisfied that the BMA took sample of protesters' blood for testing without permission and announced that the sample's was contaminated with HIV and other dangerous viruses," the core leader said.

Early Saturday, Veera Musigapong, another core leader and Chairman of UDD, said that he may lead red-shirted supporters to rally at the head office of the National Anti-Corruption Commission.

The protesters might have to use violent means, such as setting fire to the office because the agency has been using double standard towards the red-shirts movement, he said.

Around 10 a.m., the red-shirted protesters began their march in two processions.

Natthawut Saikua, a core leader and spokesman for the movement, said that one group would march to central Bangkok to oust the government while the second would move along the Vibhavadi-Rangsit Road.

They would stage another march on Sunday if the prime minister refuses to dissolve the parliament, he said.