Security forces acted to stop protesters, who were chanting anti-government slogans, from reaching the interior ministry, AFP reporters said.

Rampaging youths hurled rocks at buildings to break the windows and threw up barricades to impede the police who were not able to disperse them with tear gas and warning shots.

Three people were killed when an anti-government protest in Tunis on Saturday turned violent as riot police and masked police in civilian clothes fired warning shots and tear gas at hundreds of protesters.

Protesters are demanding the removal from the interim government of members of the regime of Zine El Abidine Ben Ali, whose toppling on January 14 after weeks of protests sparked similar uprising across the Arab world.

In the biggest of several rallies against the transitional authority, about 100,000 protesters marched down the capital's main avenue on Friday shouting slogans, including against Prime Minister Mohamed Ghannouchi who was in Ben Ali's government.

Ben Ali's fall after 23 years in power sparked similar uprisings against long-time rulers in the region, including one that led to the downfall of Egyptian president Hosni Mubarak on February 11 and another under way in Libya.