More than 400 people have died since Sunday in violent clashes between Islamic militants and security forces in Nigeria's northern states of Yobe and Bauchi.

Militants attacked a police station in northern Nigeria on Sunday. Police said Monday at least 55 people died in the attack.

It was the worst violence Nigeria has seen in months.

The Nigerian government has deployed troops to the region and imposed a curfew to try and stop any further violence.

Several leaders of the organization have since been arrested, however, Nigerian army troops are still exchanging fire with the militants a day after President Umaru Yar'Adua insisted the military had the situation under control.

The militants belong to a group that's trying to impose Islamic Sharia law across Nigeria.