Emmanuel Akimoto

The airstrikes hit a remote market in the northeastern state of Borno, where the Boko Haram insurgency began and where the Nigerian military have been fighting Islamist militant groups.

In earlier incidents, Nigeria's air force killed at least dozens of civilians in airstrikes rather than the militants it targeted.

The air force has blamed intelligence failings and operational errors.

In February, about 100 US soldiers arrived in the region

in a security pact including sharing intelligence and training Nigeria's armed forces.

Emmanuel Akimoto, NPR News, Lagos.