“The mud huts of Issa Abba’s village in Cameroon collapsed as Nigerian warplanes flew into the neighboring country one night last month and began bombing encampments nearby. Nigeria’s military said the air and ground raid—conducted under the terms of a bilateral treaty with Cameroon—killed 60 Islamic insurgents. But Cameroonian officials dispute the claim.”
Source: Nigeria’s Boko Haram Insurgency Spills Into Neighboring Countries – WSJ.com