HARGEISA(Wajaalenews);Boko Haram leader Abubakar Shekau was speaking in a video released to congratulate his fighters for seizing the town of Gwoza earlier this month.

It is not clear if Mr Shekau has pledged allegiance to Islamic State, which controls parts of Iraq and Syria.

Nigeria’s army has rejected the claim as “empty”.

Thousands of people have been killed, mostly in north-eastern Nigeria, since 2009 when Boko Haram began its insurgency.

Gwoza, which had 265,000 residents in the last census, is the biggest town under Boko Haram control.

A picture taken on August 21, 2014 shows Internally Displaced People (IDP) standing outside a classroom

“Thanks be to Allah who gave victory to our brethren in Gwoza and made it part of the Islamic state,” Mr Shekau said in the 52-minute video.

It controls several areas, mostly in Borno state where the group was launched, but also in neighbouring Yobe state.

The video also shows about 20 men in civilian clothes apparently being shot dead.

Nigeria’s military spokesman Chris Olukolade responded with a statement dismissing the declaration.

“The sovereignty and territorial integrity of the Nigerian state is still intact,” he said.