From now on, Arabic will be obligatory in all documents, advertisements, films and public speeches. Fines will be levied on anyone who breaches the law by using another language such as French, which is widely spoken in Algeria, particularly in urban areas.

The law is fiercely opposed by the Berber-speaking minority who want their language given equal status with Arabic. The Berber Cultural Movement has called for protests against the new legislation.

'Apeasement'

Berber activists say that the new law is a heavy-handed attempt by the government to appease its Islamist opponents and shore up its nationalist credentials. They have long campaigned to have their own tongue recognised as an official language.

Supporters of Arabisation argue that recognising Berber as an official language would undermine Arabic and leave French as the only language that Algerians have in common.

The introduction of the Arab language law comes on the 36th anniversary of Algeria's independence from French colonial rule.

School education has been conducted in Arabic for some years, and younger Algerians are generally more proficient at the language than their elders.

Berber opposition

Lounes Matoub: poked fun at Islamists and the government

There have been several violent demonstrations against the law since the killing last week of one of the most famous Berber singers, Lounes Matoub - who is believed to have been murdered by Islamic militants.

Thousands in the Berbers took to the streets in protest at his death.

More than 50,000 mourners attended his funeral and there were unprecedented scenes of public grief as the singer was buried in the garden of his home in the mountain village of Taourirt Moussa.

Matoub was shot dead when suspected Islamic militants tried to stop him at a roadblock, but demonstrators have accused the authorities of being responsible.

His songs criticised both the military-backed government and Islamic militants.