The new video produced by Boko Haram shows beheading of a pilot from a missing Nigerian Air Force (NAF) jet.
Abubakar Shekau, who was said to have been killed several weeks ago, was also on the video.
He said:"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 Koran."
in the video, there seems to be the same man who claimed to be Shekau. He says that the Shariah law is the true law of their state. Then the caption shows some examples of punishments: amputation of hand of the young thief, stoning of a man accused of adultery.
The video ends with an image of a burnt plane. In the video Shekau claims to have brought down 10 military aircrafts.
The video also shows a man standing on his knees in a camouflage. The fighter is standing over him with an axe. Later the captured officer is beheaded.
The victim introduced himself a wing commander of the Nigerian Air Force. He says he was undertaking a mission in Kauri area, Northeastern part of Borno State on September 11, 2014.
"We were shot down and our aircraft crashed," he says. "To this day I don't know the whereabouts of my second pilot."
The United States still give a $7 million prize on Shekau's head, despite the death claims.
Below, see the initial video that emerged on September 2.