The Catholic bishop of a diocese at the centre of the Boko Haram insurgency has said that the attacks are "demonic" and the battle is spiritual and not purely physical.

"The battle against Boko Haram should not be limited to the physical realm, but it needs to be fought in the spiritual realm for it is a demonic attack," Bishop Oliver Dashe Doeme of Maiduguri told reporters.

The bishop praised the current Nigerian government for its successes in the ongoing war against terrorism but urged it to end all violence in northeastern Nigeria, where there were still pockets of attacks and suicide bombings.