Boko Haram attacked a prison in Niger for the second time this year as the Islamist militant group continues its campaign outside its base of Nigeria.
Three members of the group and a gendarme were killed in the fight early Sunday, Maina Ary and Moustapha Ali, witnesses to the battle, said by phone from Diffa. The town is less than 5 kilometers (3.1 miles) north of the border with Nigeria.
Boko Haram fighters have expanded their attacks into Nigeria and Chad, where the group sent suicide bombers to the capital Ndjamena for the first time in the past month. Nigerian President Muhammadu Buhari has said he will defeat Boko Haram, which has killed at least 5,500 civilians since since the start of 2014, as it tries to impose its version of an Islamic state in Nigeria.