Boko Haram: Abubakar Shekau dismisses claims of his death in new video

Why did it take him lon to re-appear? Anyway, according to BBC boko haram leader is still alive.
 According to them, " A video has been released showing the purported leader of Nigeria's Islamist group Boko Haram dismissing the military's allegations that he is dead.

In the video, Abubakar Shekau says his fighters shot down an air force jet that went missing three weeks ago.

Last week, the military claimed a man posing as the Boko Haram leader in videos had been killed and in August 2013 said that Shekau may be dead.

Security analysts have questioned the credibility of the military's claims.

Nigeria journalist Ahmad Salkida, who has good contacts within Boko Haram, said on his Twitter account last week that he had it "on authority that Shekau is well and alive".

Is it is not clear when or where the video, obtained by the AFP news agency, was made.

But the BBC's Hausa Service editor, Mansur Liman, says the man speaking appears to be the same Abubakar Shekau in other Boko Haram videos.