Over 100 people were reported killed in Maiduguri and in Potiskum, Yobe state, militants set fire to a police station and murdered one of the firefighters attempting to put out the blaze.

The militants also reportedly murdered civilians at random.

President Umaru Yar'Adua, who is himself a Muslim from the north, has ordered security forces to take whatever action is necessary to restore order.

Analysts say that while the group has caused chaos in the last few days, it is too early to say if it will emerge as a major threat to security in the impoverished north.

The north has been gradually implementing stricter Islamic law, which has led to trouble with Christian groups.

Clashes in Bauchi earlier this year left five people dead and several churches and mosques gutted by fire.

Hundreds died in the city of Jos, the capital of Plateau State, last November when local elections degenerated into bloody clashes.