Boko Haram's leader said he has created an Islamic caliphate in a northeast Nigeria town seized by the insurgents earlier this month, in a video obtained by AFP on Sunday.
"Thanks be to Allah who gave victory to our brethren in (the town of) Gwoza and made it part of the Islamic caliphate," Abubakar Shekau said in the 52-minute video.
He declared that Gwoza, in Borno state, now has "nothing to do with Nigeria."
Boko Haram is blamed for more than 10,000 deaths since 2009, throughout an insurgency aimed at creating a strict Islamic state in the north.
The crisis has intensified in recent months.
Boko Haram is believed to be in control of large swathes of territory in Borno, its historic stronghold, as well as at least one town in neighbouring Yobe state.