Some 21 of the Chibok schoolgirls kidnapped by Boko Haram Islamic extremists more than two years ago have been freed in negotiations, officials said.
Some 197 girls remain captive, though it is not known how many of them may have died.
The freed girls, the first to be released as a result of government action, are in the custody of Nigeria’s Department of State Services, the secret intelligence agency.
Presidential spokesman Garba Shehu said their release was negotiated between the government and Boko Haram in talks brokered by the International Committee of the Red Cross (ICRC) and the Swiss government.
He said negotiations will continue for the release of the other students.
“We are extremely delighted and grateful,” said the Bring Back Our Girls movement. The group, which has campaigned within Nigeria and internationally for their release, said it awaits the names of the freed girls.
Boko Haram has offered to free the girls in exchange for detained leaders of the group. It is unclear if an exchange has taken place.
The ICRC has in the past tried to negotiate a swap but it failed. Information minister Lai Mohammed said negotiations last year ended when Boko Haram demanded a huge ransom for the girls’ freedom.
The abduction of 276 schoolgirls in April 2014 and the government’s failure to quickly free them has caused international outrage and brought Boko Haram, Nigeria’s home-grown Islamic extremist group, to the world’s attention.
Dozens of the girls escaped on their own, but most remain missing.
One of the girls, Amina Ali Nkeki, escaped in May on her own. She told her family that some of the kidnapped girls have died of illness and others, like her, have been married to fighters and are pregnant or have babies, her mother said.
Since then Ms Nkeki has been in the custody of the secret service where she is receiving medical care and trauma counselling, according to President Muhammadu Buhari’s government.
The government has been criticised for keeping her isolated. The Bring Back Our Girls group and Human Rights Watch have asked whether Ms Nkeki is a detainee of the government.