Muslim and Christian religious and ethnic groups skirmished in the cities of Potiskum in northeastern Yobe state, Kontagora in northern Niger state and Enugu, capital of southeastern Enugu state.

The violence followed further protests over the publication in Europe of controversial cartoons of the prophet Mohammad that have enraged Muslims worldwide.

The fighting is the worst to hit Nigeria since 2004, when Muslim-Christian skirmishes in northern Nigeria's Plateau and Kano states killed more than 700 people.