A source with contacts within the extremist group led by Abubakar Shekau said airstrikes in Balla village in Borno state on 28th April left several commanders dead.
The anonymous individual told AFP: "The reason why the aerial bombing in Balla forced him [Shekau] to seal the deal was he had lost many commanders and badly needed replacements."
Several Boko Haram leaders were released as part of an agreement which was negotiated by the Swiss government and International Red Cross. It saw 82 youngsters freed at the weekend.
The source said the schoolgirls - many of whom are Christians - were freed in a forest on the border with Cameroon on Saturday, following weeks of negotiations. They later met Nigerian President Muhammadu Buhari.
They were among 276 taken from the predominantly Christian village of Chibok in northern Borno state overnight on 14th-15th April 2014.
A military source told AFP the military had been increasingly well-informed on the movements of fighters.
He said: "We foiled attempts to attack multiple locations in the past week, including Maiduguri, Konduga, Kumshe and Bama (all local areas) based on intelligence reports."
It is also thought infighting between different Boko Haram factions has left the group weakened.
Boko Haram has been behind an insurgency in Nigeria and neighbouring countries which has left 20,000 people dead since 2009.