A group of girls released by Boko Haram jihadists after they were kidnapped in 2014 in the north Nigerian town of Chibok have arrived in the capital Abuja, a witness said.
The girls arrived at Abuja airport and were driven away in a military convoy.
Nigeria said it had secured the release of 82 girls in exchange for Boko Haram prisoners.
Around 270 girls were kidnapped in April 2014 by the Islamist militant group, which has killed 15,000 people and displaced more than two million during a seven-year insurgency aimed at creating an Islamic caliphate in northeastern Nigeria.
Dozens escaped in the initial melee, but more than 200 remained missing for more than two years.
Nigeria thanked Switzerland and the International Committee of the Red Cross for helping secure the release of the 82 girls after "lengthy negotiations", the presidency said in a statement.
President Muhammadu Buhari will receive the girls this afternoon in Abuja, it said, without saying how many Boko Haram suspects had been exchanged or disclosing other details.
A military source said the girls were brought this morning from Banki near the Cameroon border to Maiduguri, the capital of Borno state where the insurgency started.
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The release of the girls may give a boost to Mr Buhari who has hardly appeared in public since returning from Britain in March for treatment of an unspecified illness.
He made crushing the insurgency a pillar of his election campaign in 2015.
The army has retaken most of the territory initially lost to the militants but attacks and suicide bombings by the group have made it nearly impossible for displaced persons to return to their recaptured hometowns.
More than 20 girls were released last October in a deal brokered by the International Committee of the Red Cross. Others have escaped or been rescued, but 195 were believed to be still in captivity.
Mr Buhari said last month that the government was in talks to secure the release of the remaining captives.
Although the Chibok girls are the most high-profile case, Boko Haram has kidnapped thousands of adults and children, many of whose cases have been neglected.
Although the army has retaken much of the territory initially lost to Boko Haram, large parts of the northeast, particularly in Borno state, remain under threat from the militants. Suicide bombings and gun attacks have increased in the region since the end of the rainy season late last year.
