Nigeria's army says soldiers on Sunday killed 30 suspected Boko Haram members during a gunfight in northeastern Yobe state.
A spokesman says a senior aide to Boko Haram's leader was among those killed. Nigerian soldiers seized a number of weapons including rifles, knives and bows and arrows.
The army says it arrested 10 Boko Haram suspects who it says are helping troops track down other members.
There is no word on any army casualties.
Boko Haram is an Islamic militant group that is trying to set up a strictly conservative Islamic state in Nigeria. Authorities blame the group for killing more than 1,400 people. Churches and police are frequent targets.