Up to 80 girls kidnapped by Boko Haram in 2014 have been released a Nigerian official has confirmed.

The girls were among 276 who were abducted by the militant group from their school in the northern town of Chibok in north-eastern Nigeria on 14 April.

An official whose own two daughters were among those kidnapped confirmed the girls were released through negotiations with the government. "I can confirm they have been released," he said in a statement.

The girls are being held in Banki near the Cameroon border where they are undergoing medical checks before being airlifted to Maiduguri BBC News reports.

Last month Nigerian President Muhammadu Buhari said the government was engaged in talks to secure the release of the remaining captives and was working "through local intelligence to secure the release of the remaining girls and other abducted persons unharmed".

Last October Boko Haram released another 21 girls after negotiations with the Red Cross. While the latest news is a source of hope for the people of Chibok, over 100 girls are still being held captive by the insurgents.

Meanwhile a Nigerian government spokesman said a statement would be released with more details of the girls' release.

The mass abduction in 2014 prompted a global outcry and a social media campaign supported by then US First Lady Michelle Obama with the hashtag #bringbackourgirls

During its eight-year insurgency Boko Haram have killed over 30,000 people and kidnapped hundreds.

The terrorist group fights against Western influence in Nigeria and aims to impose its version of Sharia law throughout occupied territories forcing the communities to convert to Islam in a bid to create an Islamic caliphate in north-eastern Nigeria.

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The abduction of the girls from Chibok in 2014 sparked a global outcry Afolabi Sotunde/Reuters