Witnesses said the trouble spread to Kotangora and Potiskum in  northern Nigeria on Friday. Three people were killed in by Muslim rioters in Kotangora and nine churches were burnt. One suspected northerner was reported killed in Enugu in the Igbo-dominated southeast by a Christian mob.

The latest sectarian violence began last Saturday in Maiduguri, in  the predominantly Moslem north. At least 30 Christians were killed by Muslims protesting a cartoon of Prophet Mohammed in a Danish newspaper. It later spread to other towns of Bauchi and Katsina, with dozens of Christian casualties.

On Monday,  reprisal killings took place in the commercial town of Onitsha when bodies of some of the victims were brought back to the mainly Christian south east.  Over 50 northernors were killed in the violence.

The attacks have been condemned by leaders of both religious groups but the mobs have refused to stop the killings. Observers have criticised the government for failing to prevent the riots from spreading almost a week after it began.

One analyst said it could consume the whole nation unless quick action is taken.

Although the government has ordered troops to assist in quelling the trouble, the country remains tense -- amid fear of further outbreaks.