Hundreds of anti-government supporters in Bangkok shaved their heads on Thursday in protest at Thai Prime Minister Abhisit Vejjajiva's government.

Men, women and children from the so-called Red Shirts protest group took part in this latest action.

The protesters want the Thai Prime Minister to dissolve Parliament and call new elections.

Many have been camping out on the streets of Bangkok since March 14, demanding the dissolution of parliament and calling for fresh elections.

Protest leader Suporn Atthawong warned Abhisit that if he "insists on staying in power, we'll use tougher measures in the future."

On Wednesday, Thailand's political battleground had shifted to Parliament, where opposition lawmakers boycotted proceedings in a protest against tight security imposed by the military amid the Red Shirt anti-government rallies.