LAGOS , Nigeria ( CNN ) -- More than 2,500 Nigerians caught in the fighting between Islamic militants and government forces have fled their homes in the northern part of the country , a Red Cross spokeswoman said Wednesday . Mothers and their children take refuge this week at a police office in the northern Nigerian city of Maiduguri . More than 400 people have been killed , and 150 bodies were lying in the general hospital at Maiduguri , according to Aliyu Maikanu , a Red Cross disaster officer in the northeast . Most of the violence has been on the outskirts of the city , officials said . `` It 's a terrible situation for me . It 's a very serious battle -- something I have not seen in my life , '' Maikanu said . She said only security personnel were free to move around due to the risks . Up to 1,000 militants are holed up at their base of operations in Maiduguri , and police have cordoned off the area , she said . National police spokesman Emmanuel Ojukwu said Wednesday that police were able to free 187 women and children whom they claim were being held in the compound of the Islamic militants ' leader , Mohammed Yusuf . Under the sect 's strict form of sharia law , the group that was released was shielded from public view , Ojukwu said . He said 100 arrests have been made across the north . Shehu Sani , president of the Civil Rights Congress , a human rights organization based in northern Nigeria , said people were seeking refuge in police and military barracks and in hospitals . The militants disagree with the government 's teaching of Islam in the region , maintaining that the government allows itself to be influenced by Western values . They have been targeting high-profile government institutions , police and Islamic clergy , Ojukwu said . The operation to defeat the militants is ongoing , he said , and police have been deployed in all northeast and northwestern states . There is a history of religious violence in central Nigeria , where majority-Muslim North Africa meets largely Christian sub-Saharan Africa . Human Rights Watch estimates that more than 1,000 people were killed there in riots in 2001 . Last week the human rights organization alleged that police and soldiers killed at least 133 people during two days of riots last year between Muslims and Christians in Nigeria . Most of the victims were young Muslim men , often unarmed , the group said in testimony before a state commission . CNN 's Christian Purefoy contributed to this report .
NEW : More than 180 women , kids freed from militants ' compound , official says . More than 2,500 flee fighting between militants , government in northern Nigeria . More 400 people killed in Nigerian violence , Red Cross official says . Militants holed up at base of operations in Maiduguri , Nigeria .