Twelve soldiers in southeastern Niger were killed and eight wounded in an overnight attack by gunmen likely belonging to Islamist insurgent group Boko Haram, the defense ministry said on Wednesday.

Boko Haram has been fighting for a decade to carve an Islamist caliphate out of northeast Nigeria, and has carried out regular raids over loosely guarded borders into neighboring Chad, Niger and Cameroon.

On the night of Oct. 29-30, an army position in Diffa region was “attacked by unidentified armed persons very probably belonging to the terrorist group Boko Haram,” the ministry said in a radio statement.