Boko Haram issues threat over US-made anti-Islam film

The suspected leader of Nigerian Islamist extremist group Boko Haram has issued a threat in a YouTube video over a US-made anti-Islam film that has sparked widespread protests in the Muslim world.

"First, insults against the prophet, evil plots against him, making blasphemous movies against him, all these will do no harm to Islam," Abubakar Shekau says in the Hausa language spoken throughout Nigeria's north in the video which appears to have been posted on Sunday.

"Anybody plotting this will surely pay for it. Everybody knows what this statement entails. Everybody should wait and see what we will do regarding this."

The video could not be independently authenticated, but it closely resembled previous such videos of Shekau, who has been in hiding since a 2009 crackdown by Nigeria's military on Boko Haram.

A number of protests over the anti-Islam film have been held in Nigeria's mainly Muslim north organised by a Shiite Muslim group not connected to Boko Haram, with no violent incidents occurring.

In the nine-minute video, Shekau, an AK-47 leant on the wall next to him, also threatens Nigerian authorities, says he is prepared to die and denies government assertions that there has been dialogue with his group.