Sambisa forest is believed to be the last stronghold of Boko Haram militants.
It is also believed to be the place where the missing Chibok girls might have been held hostage.
Reports have it that the military backed off owing to landmines planted by the terrorists on the roads leading to the Sambisa forest.
According to the Director, Defence Information, Major Gen. Chris Olukolade, the terrorists have run out of sophisticated arms and ammunition as they now roam around the bushes on the fringe of the forest with crude weapons.
Nigerian, Cameroon, Chadian and Nigerien armies have in the past two months launched combined operations to crush the Boko Haram insurgents, who have killed thousands and kidnapped hundreds in the past few years in their course to establish an Islamic state.
The Sambisa forest is a vast former colonial game reserve in the north eastern region of Nigeria, which is about 100 km (60 miles) from the Chibok village where the terrorists group kidnapped more than 200 secondary school girls on April 14th, 2014.