The BBC's Barnaby Phillips: Police admit they lack manpower

Thousands more Yorubas - who are an ethnic minority in the Hausa-dominated north - are said to be sheltering at police stations and military barracks in the city, fearing further attacks.

Police have announced that a police station was attacked during riots on Sunday night.

Press reports said many people had been killed in a stampede as those seeking shelter - most of them Yorubas - fled the attackers.

Police sources say at least 70 people have died in the recent conflict between Yorubas and Hausas - Nigeria's two largest ethnic groups.

The city is now reported to be calm, after troops were called out to help quell the fighting.

BBC Nigeria Correspondent Barnaby Phillips says the extent of the violence is clear in the northern suburbs of Kano, where many Yoruba-owned shops, houses and cars have been burnt and destroyed.

Hospitals are treating injured members of both ethnic groups. Some of the victims bear gruesome machete wounds.

The police have blamed the violence on what they call hooligans, driven more by the desire to loot than by ethnic hostility.

Regional dominance

Hausas are the largest community in Kano, northern Nigeria's largest city, while Yorubas dominate the south-west of the country.

But both regions contain substantial minorities.

Most Yorubas are Christian, while Hausas are mainly Muslim.

Tension between the Hausas and Yorubas has been high since fighting in the southern city of Sagamu 10 days ago, in which at least 50 people died.

After the fighting in Sagamu, which is in a predominantly Yoruba area, many Hausa people fled to Kano, adding to the tensions there.