Niger and Chad forces stormed the most trusted Boko Haram hideouts on islands on Lake Chad on Monday military sources in Niger said.
According to a Chadian officer, about 50 Boko Haram militants died in the operation that also claimed two Chadian soldiers.
The operation has driven Boko Haram from most of the positions it controlled earlier this year, and from which they waged deadly attacks against Nigerians, shooting and maiming their victims.
Analysts say Boko Haram fighters are likely to revert to a campaign of hit-and-run attacks now they have been driven from the main towns they once controlled.
The attacks are responsible for Nigeria’s delaying the presidential vote that would have been done early February.
Nigeria’s rearranged election was held on Saturday, with millions voting despite militant waged violence that claimed at least a dozen people.