Abuja - Nigeria's information minister said Thursday that the release of 21 of the more than 200 Chibok girls abducted by Boko Haram more than two years ago was not a prisoner swap.
"Please note that this is not a swap. It is a release, the product of painstaking negotiations and trust on both sides," Lai Mohammed told reporters in Abuja, denying claims from local sources that the girls were freed in exchange for four Boko Haram prisoners.
The minister said the release followed intensive negotiations with Boko Haram leadership.
"As soon as the necessary confidence was built on both sides, the parties agreed on the date and the location of the release of the 21 girls," he said.
The government would continue to pursue the release of the remaining girls, he said, adding that those freed would receive medical attention and care.
"We see this as a credible first step in the eventual release of all the Chibok girls in captivity. It is also a major step in confidence-building between us as a government and the Boko Haram leadership on the issue of the Chibok girls," he said.
Also read: FG confirms release of 21 Chibok girls
Mohammed said the government would release the names of the girls after contacting their parents and verifying their identities.
Nigeria announced last month that it had opened negotiations with Boko Haram to secure the release of the abducted girls, but revealed that the talks were derailed due to a divisions in the jihadist group.
Previous efforts to negotiate with the group also failed.
Boko Haram had insisted the girls would only be released in exchange for its members being held in government custody.
In April 2014, 276 girls were seized from their accommodation in the northeast town of Chibok as part of Boko Haram's campaign to establish an Islamist state in the region.
Scores of the girls escaped in the hours after the kidnapping, while another was rescued earlier this year.
The mass abduction drew global attention to the jihadist insurgency which has claimed some 20,000 lives and forced at least 2.6 million more to flee their homes since 2009.