At least four people were killed in an attack by Boko Haram militants in north-eastern Nigeria late on Thursday, the national emergency agency said on Friday, the second such clash in Maiduguri city in a month.

Five suicide bombers were also killed in the attack, which Nigeria’s military said had been repelled by troops supported by the air force, police and other security agencies.

Blasts and gunfire were heard by residents in the city which is the capital of Borno, the state worst hit by the insurgency aimed at creating an Islamic caliphate in the northeast which has killed more than 34,000 people since 2009.

The signs of battle were still clear, with the charred body of a man among the tents in a camp for people displaced by the conflict, and an unexploded bomb dropped by the Nigerian air force lying nearby.