Five Nigerian soldiers were killed by Islamic State-aligned jihadists and dozens of civilians were kidnapped in a separate attack, military sources said Sunday, in the latest violence to grip the north of the country.

A military convoy was hit in northeast Borno state on Saturday, and militants also attacked a transport convoy in the same region a day before, abducting 35 people and killing one woman.

Nigeria’s Boko Haram and a splinter group, the Islamic State West Africa Province (ISWAP), have killed 36,000 people and displaced around two million as part of a decade-long conflict.

Deadly attacks and kidnappings by jihadists in the northeast and criminal gangs in the northwest have intensified in recent weeks.

Saturday’s attack on the military convoy took place outside of Mafa, 44 kilometres (27 miles) north of the regional capital Maiduguri.

“The terrorists fired an RPG (rocket-propelled grenade) on the convoy which hit one of the vehicles with five soldiers in it,” one security source said.

“All the five were killed.”

The insurgents seized two vehicles in the attack, said a second source who gave the same toll.

ISWAP split from the mainstream Boko Haram six years ago and rose to become a dominant group.

The jihadist group focuses on military targets, raiding bases, ambushing troops and planting mines on the roads, but recently they have been attacking and abducting civilians.

Dozens were kidnapped late Friday by ISWAP militants at a fake checkpoint in Garin Kuturu village outside Jakana, 25 kilometres from Maiduguri.

“The ISWAP terrorists who were dressed in military uniform stopped the vehicles… Some of the passengers fled into the bush while 35 were taken hostage,” a pro-government militia official said.

A woman was shot dead and several others were injured when the militants opened fire on those fleeing into the bush, he said.