File photo showed the released 21 Chibok school girls waited to meet Nigerian President Muhammadu Buhari at the State House in Abuja, Nigeria, Oct. 19, 2016. (Xinhua/Olatunji Obasa)

LAGOS, Dec. 15 (Xinhua) -- The Nigerian Army said on Wednesday ground troops in different patrols rescued 605 people held hostage by Boko Haram insurgents in Sambisa forest.

Lucky Irabor, Theater Commander of Operation Lafiya Dole, told a news conference in Maiduguri, the restive northeast Borno state capital, that 69 male adults, 180 females, 227 male children and 129 female children, were rescued during the operation between Dec. 7 and Dec. 14, 2016.

"The victims are in our custody for further investigation and interrogation," he added.

Many areas have been cleared, while many hostages have been set free and scores of insurgents killed in different patrols conducted by Nigerian troops across the region.

Nigeria's northeast region has been a stronghold of the extremist group Boko Haram. Over past months, the Nigerian government has launched several military operations to eliminate the terrorist threat.