The army says Nigerian troops have driven Boko Haram extremists out of an abandoned northeastern primary school in a shootout that killed four militants.

An army statement says the insurgents were using the school as a transit camp until Sunday's attack.

Boko Haram — which means "Western education is forbidden" — has committed many atrocities at schools that have closed, been burned down or been abandoned in much of northeastern Borno state. The U.N. Children's Fund says 10.5 million children are out of school in Nigeria — the highest number in the world — and that only half of children among 2.3 million refugees from the uprising are going to school in camps.