According to Algerian newspaper reports on Tuesday, hundreds of youths set fire to public buildings in the town of Birina, in the Jilfa region 270kms south of Algiers.

Security forces used tear gas against the demonstrators, carrying out several arrests, the reports said.

Meanwhile in the country's northeast, angry demonstrators in the town of Khirrata reportedly blockaded the region's main road.

17% increase

Butane gas and fuel oil are the only available sources of energy in Algeria's remote mountain regions and high plateaus.

The government's decision to raise the price of a litre from 170 to 200 dinars ($2.3 to $2.8) goes against a recommendation from the national parliament.

Hostility to Algerian authorities erupted into bloody unrest in 2001, claiming at least 100 lives and leaving dozens more injured.

The government in Algiers at the weekend reached an agreement with the region's tribal leaders, which includes economic demands and recognition of the language spoken by the ethnic Berbers who live mainly in the region.