Nigeria's army claims to have rescued at least a dozen women and children kidnapped by Boko Haram.

They were freed on Monday when the army cleared Boko Haram camps in Borno state, according to military spokesman Colonel Sani Kukasheka Usman.

Details of who the women and children were, where they were kidnapped or their condition upon release have not been released.

This year hundreds of hostages have been freed from Boko Haram, however none of the 219 girls abducted from a school in Chibok in April 2014 have been found.

There is fear that they have been killed in suicide bombings, as Boko Haram have frequently used girls for such attacks in Nigeria, Chad, Cameroon and Niger.

The Islamic extremist group has declared an Islamic caliphate aligned with Islamic State in the Middle East.

Despite a pledge to annihilate the militants, more than 1,000 people have been killed since President Muhammadu Buhari was elected in March. During the six year old uprising, at least 2.1 million people have been forced to flee their homes.