Seventy Nigerian soldiers died in an Islamist militant ambush in Borno state, military and security sources told Reuters.
The attackers used rocket-propelled grenades and heavy weaponry in Gorgi village on Monday. Injured soldiers were brought to Maiduguri and bodies of the dead were taken to Maimalari military hospital.
Military spokesman Sagir Musa confirmed an attack, but disputed the number of soldiers killed. He declined to give more details.
It was not immediately clear who the attackers were. Militants from the Boko Haram and the Islamic State West Africa Province groups are active in the region.