Witnesses say two suicide bombers killed an Air Force officer at a checkpoint in a late-night attack in Nigeria's northeastern city of Maiduguri.

They blamed the attack on Boko Haram Islamic extremists responsible for a slew of such attacks that have killed hundreds this year in Nigeria and neighboring Cameroon, Chad and Niger.

Tuesday night's explosion occurred hours after Nigeria's military ordered officers to report for duty to a new multinational army based in N'Djamena, Chad's capital, to launch a long-delayed offensive against Nigeria's home-grown insurgents.

A self-defense fighter said a lieutenant died and a woman was injured when two suicide bombers approached a checkpoint and one exploded. He insisted on anonymity because he was not authorized to speak to the press.