The Islamist militant group Boko Haram has released 13 people who were kidnapped in north-eastern Nigeria last year.
The Nigerian government said those released include 10 women seized during an attack on a police convoy and three lecturers from Maiduguri taken during an oil exploration trip.
President Muhammadu Buhari’s office said their release was facilitated by the Red Cross.
About 20 000 people have died in Boko Haram’s eight-year insurgency.
In a statement, the International Committee of the Red Cross (ICRC) said it had acted only as a neutral intermediary and were not involved in the negotiations.
ICRC vehicles arrived at a refugee camp on the Cameroon border at about midday today, sources quoted by the AFP news agency said.
They drove into the bush and returned some hours later with the 13 who were then flown in four helicopters to Maiduguri.
Details of the negotiations were not revealed.
In October 2016 and May 2017 the ICRC was also an intermediary in the release of some of the 200 girls kidnapped by Boko Haram from the town of Chibok in 2014.
Mr Buhari today called on the Nigerian army to intensify efforts to bring home more than 100 Chibok schoolgirls still missing.
Boko Haram is fighting to overthrow the government and create an Islamic state.