LIKE ISIL, LIKE BOKO HARAM ... MORE DESPERATE MOVES : Boko Haram Video Shows Beheading of Nigeria Pilot ... ABCNews

Boko Haram, the extremist Islamic group In NIGERIA, has published a video that shows charred plane wreckage and the beheading of a man identified as a pilot of a missing Nigerian Air Force jet, bolstering the group's claims that it shot down a fighter plane.

The video also allegedly features Boko Haram leader Abubakar Shekau, a man NIGERIA's military twice has claimed to kill — first in 2009 and again last year. Two weeks ago the military said they had killed a Shekau lookalike who had posed in the group's videos.

"Here I am, alive, and I will remain alive until the day Allah takes away my breath," the man says in the Hausa language. "Even if you kill me ... it will not stop us imposing Islamic rule ... We are still in our Islamic state, reigning and teaching the Quran."

The United States still has a $7 million bounty on Shekau's head.

The video was made available to The Associated Press through the same channels used previously and seems to show the same man. Nigeria's Defense Headquarters suggested in a blog that the insurgents had manipulated images and cloned "another Shekau."

In the video, the man identified as Shekau says Boko Haram is implementing strict Shariah law in areas of northeast Nigeria under its control. Examples are shown, including the stoning death of a man apparently accused of adultery; the amputation of the hand of a young man accused of theft; the lashings of a man and what appears to be a girl covered in a hijab.

The video ends with a show of burnt-out plane parts in rugged bush. Two pilots and an Alpha jet have been missing since Sept. 11 when it left the northeastern town of Yola on a bombing mission against Boko Haram.

The video shows a kneeling man in a camouflage vest with his right hand in a sling, with a fighter hovering over him with an ax, which is later used in the beheading.

Speaking in English, the victim identifies himself as a wing commander in the Nigerian Air Force and says he was undertaking a mission in Kauri area of northeast Borno state.

"We were shot down and our aircraft crashed," he says. "To this day I don't know the whereabouts of my second pilot."

The insurgents have stolen military hardware from Nigerian forces, probably including anti-aircraft weapons.