Heavy snow and strong winds have hit northern Algeria over the past 24 hours, causing nine deaths and isolating parts of the oil-producing North African country, authorities said yesterday.

Snow paralysed the northern cities of Constantine and Skikda, site of Algeria's most important oil refinery. It was not immediately clear whether the 335,000 barrels per day refinery was affected.

Authorities warned of more snow and strong winds. Other parts of North Africa were not as badly affected.

Schools and public administrations were shut yesterday in Skikda, 400km east of the capital Algiers. Several key roads in the north, including the Skikda-Constantine motorway, were closed.

Some of the region saw snow up to 1.2 metres deep. Parts of the desert were also covered in snow, said state radio. Snow in Algiers - highly unusual - paralysed traffic in several areas of the Mediterranean capital and caused numerous traffic accidents.