Boko Haram rejected claims from Nigeria's military that it has been routed by a four-nation offensive in a video released online on Tuesday, which does not show the group's leader, Abubakar Shekau.

The unidentified speaker calls Nigeria, Cameroon, Chad and Niger, who have been battling the Islamists, "the lying coalition partners" while the video bears the logo: "Islamic State in West Africa."

"Most of our territory is still under our control," said the speaker, whose face is not shown in the 10-minute message posted on YouTube.