At least 33 Boko Haram militants were killed by Nigerian troops in a gunfight on Sunday, said military sources on Tuesday.
Multinational troops fighting Boko Haram along the Lake Chad fringes also joined in the gunfight, said the sources who asked to be anonymous.
The multinational force comprises troops from Nigeria, Chad, Cameroon, Niger, and Benin.
The gunfight lasted for about three hours, along the Gamboru-Dikwa road in Borno, one source said, as the Boko Haram militants had laid an ambush for a convoy of military vehicles.
"Many Boko Haram fighters fled with bullet wounds. It was a tough battle," said the source.
One other military source confirmed four soldiers, however, sustained injuries during the gunfight.
Two gun trucks used by the militants were recovered after the gunfight, the source said.
The northeast region of Nigeria has been destabilized for over a decade by Boko Haram.
Boko Haram is known for its agenda to maintain a virtual caliphate in the most populous African country.