The deaths happened in the town of Buni Yadi, in Yobe state, on Saturday, in an attack that the military said also killed five jihadists and four soldiers.

Army spokesman Sagir Musa said five rebel fighters "met their Waterloo" as they attempted to overrun a military base at about 6:00 pm (1700 GMT) on Saturday.

At about the same time, there were attacks on military positions in Gajibo and Gajiganna, north of the Borno state capital Maiduguri, security sources in the city said.

In Buni Yadi, local resident Aisami Lawan told AFP: "The attackers came around 5:30 pm. The fighting lasted more than two hours...

"A stray projectile hit one of the houses nearby, killing all five occupants. Eleven people were also injured from stray bullets and shrapnel."

The five dead were buried on Sunday morning, he added.

A member of the Civilian Joint Task Force militia assisting the military with security confirmed the account and said the Boko Haram fighters were killed after the attack.

"When the terrorists turned back, a detachment of CJTF was waiting and laid ambush to them," he added.

"An officer and three soldiers have lost their lives during the encounter," he said, adding that five others were wounded.

Musa said the heavily armed militants were in four gun trucks and two armoured vehicles. Troops seized weapons and ammunition, he added.

The military base in Buni Yadi has been targeted before in the conflict.

In January, two military sources told AFP the Islamic State-allied faction of Boko Haram killed four soldiers and were repelled after air support was called in.

In recent months a wave of attacks have hit the Buni Yadi area, which is near the border with Borno state -- the epicentre of fighting since 2009.

Most of the attacks on military positions and troops have been blamed on or claimed by the self-styled Islamic State West Africa Province (ISWAP) faction.

Nigeria's President Muhammadu Buhari, who was elected in 2015 on a promise to defeat the Islamist militants, maintains that the group is "technically defeated".

Buni Yadi was the scene of one of Boko Haram's most notorious attacks, when fighters loyal to long-time leader Abubakar Shekau stormed a boys' boarding school in February 2014.

More than 40 students were killed as they slept.