Several troops were also injured and four trucks were lost to the militants, a soldier said.
At least four Nigerian soldiers and a militia fighter were killed in clashes with IS-aligned jihadists in Borno State, security sources told AFP on Sunday.
Fighting erupted late on Saturday when troops ambushed a convoy of the Islamic State West Africa Province near Jakana Village, 42 kilometres from the state capital, Maiduguri.
Several troops were also injured and four trucks were lost to the militants, a soldier said.
The jihadists were riding in pick-up trucks fitted with machine guns according to a source, who confirmed the death toll.
In a statement issued on Sunday, the Nigerian military said seven jihadists were killed and eight injured when their vehicle hit a landmine during a clash near Jakana on Friday.
The improvised explosive device had been planted by the jihadists, army spokesman Colonel Aminu Iliyasu was quoted as saying.
The decade-long conflict, which spilt into Nigerian neighbours — Niger, Chad and Cameroon — has killed at least 35,000 people and forced some two million to flee their homes in Nigeria alone.