Nigeria's army is posting photographs of 100 wanted Boko Haram militants including the shadowy leader whom they claim to have killed on at least three occasions.

The poster pasted onto walls this week includes elderly men and boys who appear to be minors.

Army spokesman Col. Sani Usman says there are no names attached since most images are screen grabs from videos seized in raids on Boko Haram camps or published on the Internet by the Islamic extremists.

No reward is offered for requested information about them.

The center of the photo collage features Boko Haram leader Abubakar Shekau cradling an AK-47 assault rifle with belts of ammunition strapped to his chest.

Nigeria's military has claimed that Shekau is dead at least three times in the past three years.