Abuja: Boko Haram's leader said a northeast town seized by the insurgents earlier this month has been placed under an Islamic caliphate, 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 long video.
In a July video, Shekau voiced support for the leader of the Islamic State militants Abu Bakr Al Baghdadi, who in late June declared himself "the caliph" and "leader of Muslims everywhere".
But there was no indication from Shekau in the latest video that he was associating himself with Baghdadi, whose extremist fighters have taken over parts of Iraq and Syria.
As such, it was not clear if Shekau was declaring himself to be a part of Baghdadi's call or if he was referring to a separate Nigerian caliphate.
In the 19th century, a Sokoto caliphate was proclaimed across most of modern-day northern Nigeria and was considered separate from other Muslim kingdoms, such as the Ottoman Empire.
Shekau — who has been designated a global terrorist by the United States and sanctioned by the UN Security Council — is shown in the video wearing military fatigues, with a Kalashnikov rifle strapped to his body.
He alternates between Arabic and the Hausa language that is dominant in the region.
He is pictured standing in front of three SUVs and flanked by four fighters, who are masked and armed.
It is not clear when or where the video was filmed.
There was no indication that Shekau was actually in Gwoza for the filming and his whereabouts remain unknown but he vowed that his fighters would keep control of the area.
"By the grace of Allah we will not leave the town. We have come to stay," he said.
The United Nations humanitarian office (OCHA) earlier this month confirmed reports that Gwoza was under rebel control.
Mapping the precise areas which have fallen into extremist hands is nearly impossible.