An attack by Islamist militants on a police station in northern Nigeria Sunday has left dozens of people dead, a police spokesman said.

"A group of fundamentalists this morning attacked a police station in Bauchi state," Nigerian national police spokesman Emmanuel Ojukwu told The Associated Press. "They were armed with guns, bows and arrows and explosives. There were some casualties but I cannot say how many for now."

Ojukwu would not give details of the clash and said only that the number of dead was in the dozens. Bauchi state police spokesman Mohammed Barau said most of the dead were Islamist fighters.

Ojukwu said police arrested more than 100 fighters and that the situation in the state capital, where the attack occurred, is now calm.

Bauchi state lies along a line splitting Nigeria's predominantly Muslim and pastoralist northern population from southern Christian and animist farming communities.

In a nation of 140 million roughly split between Muslims in the north and Christians and animists in the south, Bauchi is one of 12 northern states where Islamic Shariah law is practiced. Various groups have clashed before over its proper implementation.