More than 50 Nigerians were killed on Sunday in clashes between security forces and militants in the northeastern city of Bauchi, residents and hospital sources said. The fighting began early Sunday when around 70 militants armed with guns and explosives attacked a local police station in retaliation for the arrest of their leaders. Police and soldiers repelled the attack and then raided neighborhoods to arrest at least 200 suspects. “We have preempted the militants. Otherwise the situation would have been bad,” Bauchi state Governor Isa Yuguda told reporters. “I'm calling on all the people of Bauchi to be calm and be rest assured the situation has been brought under control,” he added. The governor imposed a night time curfew in Bauchi for the next few days. Police spokesman Mohammed Barau said the militants belonged to Boko Haram, a local group that wants Shariah law to be imposed on all of Nigeria. A member of Boko Haram who was wounded during the attack told Reuters his group wanted to “clean the (Nigerian) system which is polluted by Western education and uphold Shariah all over the country.” “The police has been arresting our leaders that is why we decided to retaliate,” said the man, who gave his name only as Abdullah. The Islamic group is not connected to the Movement for the Emancipation of the Niger Delta (MEND), Nigeria's most prominent rebel group responsible for a campaign of violence that has devastated Africa's biggest energy sector since early 2006.