Authorities say gunmen from a radical Islamist sect shot and killed two guards during a prison break in northeast Nigeria.
Borno state police spokesman Samuel Tizhe said Friday the attack happened overnight Thursday near the village of Kunshi. Tizhe said gunmen first attacked a police station, then freed all the prisoners.
Tizhe said police have made 23 arrests since the prison break. It was not immediately clear how many inmates escaped from the prison after the attack.
Boko Haram is waging an increasingly bloody sectarian struggle against Nigeria's weak central government. The sect recently carried out a suicide attack and a bombing against offices of a major Nigerian newspaper.