At least nine Nigerian soldiers and two members of a civil defence militia were killed in a jihadist attack on a civilian convoy in northeast Borno state, security sources told AFP Sunday.
Several civilians were said to be missing after the ambush.
The jihadist fighters opened fire with heavy guns and rocket-propelled grenades on the convoy of more than a hundred vehicles Saturday afternoon outside Komala village near the town of Damboa, 90 kilometres (55 miles) from the regional capital Maiduguri.
Damboa lies on the fringes of Boko Haram's Sambisa forest enclave from where the group launches attacks on villages and against troops.
"Nine soldiers and two (anti-jihadist) militia were killed in the attack, " a military officer said.
"It was an ambush on a civilian convoy escorted by troops and the militia," said the military officer who asked not to be identified.
The convoy, was heading from Maiduguri to Damboa when it was attacked, according to militia leader Ibrahim Liman who confirmed the death toll.
"The bodies of nine soldiers and two vigilantes were recovered from the attack along with others who sustained injuries," Liman said.
The jihadist militants seized several vehicles and looted supplies before withdrawing to their Sambisa enclave, he added.
Several civilians were still missing and were presumed killed or abducted by the assailants, the militia leader said.
Boko Haram and its splinter Islamic State West Africa Province (ISWAP) are notorious for ambushing military and civilian convoys on highways outside Maiduguri in addition to abducting travellers at bogus checkpoints.
Civilians travelling north of Maiduguri move in convoys under military escort due to the incessant attacks by the jihadists, wich have intensified in recent weeks.
The decade-long jihadist conflict has cost the lives of 36,000 people and displaced around two million from their homes in the northeast.
The violence has also spread to neighbouring Niger, Chad and Cameroon, prompting a regional military coalition to fight the militants.