Fearing an Islamic community of almost 4,000 members might become violent, Nigerian police detained on Saturday about 3,950 people belonging to the Darul Islam group.

According to the police commissioner in the Nigerian State of Niger, the group posed a potential violent threat. Commissioner Michael Zuokumor said the members of the said sectarian group was evacuated from their main camp in a town called Mokwa. They’re being detained inside a local school building.

This police raid followed after Boko Haram, another Islamist group, caused a violent uprising where more than 700 people were killed, including authorities and militants.

Reports state that the Darul Islam camp was created as a place where members can observe their strict Islamist principles.