Anti-riot police forced their way through a make-shift barricade before the parliament building in Sofia overnight. Within two hours, the authorities transported the roughly 109 ministers, lawmakers and journalists trapped inside to a safe location, according to Bulgarian state radio and an AFP photographer on site.

On Tuesday evening, hundreds of protesters pulled out sidewalk tiles and piled garbage bins to cut off roads to the parliament building as tensions escalated on the 40th day of anti-government rallies.

Clashes erupted when police attempted to escort officials from the building in a bus. Protesters threw bottles and stones at the vehicle, while some sat in front of it blocking its path amid shouts of "Mafia!" and "Resign!" and "Red Garbage!" Police in riot gear tried to push the protesters back in an attempt to clear a path.

Local television broadcast the clashes live, showing several wounded protesters and one injured policeman. The people hurt reportedly included several with head injuries. After an hour, the vehicle was forced to return to the building.

Those trapped were thought to have included three ministers, some 30 lawmakers, journalists and parliament staff. Protesters had intended to keep up the blockade until their demands had been met.

Mass anti-government unrest

Up to 10,000 Bulgarians have taken to the streets of Sofia daily since June 14 in a bid to oust the left-leaning government.

Public discontent was initially sparked when the government announced its decision to appoint a powerful media magnate as the head of the country's powerful security agency, which many saw as proof that private interests were controlling state institutions.

Although the appointment was immediately revoked, protests had already evolved into wider anger against the cabinet ministers and government in general, which many insist is corrupt and under the influence of powerful oligarchs.

Responding to the escalation of public unrest on Tuesday, President Rosen Plevneliev issued a statement urging protesters to keep the demonstrations "peaceful and civilized."

"I appeal to the protesters to keep the protest the way it was and the way it impressed all Europe - peaceful, civilised and aimed at achieving the values of a democratic society," Plevneliev said.

The president also called on the police not to yield to the accumulated pressure and keep the protest peaceful.

"We all live here, this is our country and we are responsible towards it. I urge for calm and order," Plevneliev added.

kms, ccp/jm (AFP, Reuters, AP)