ABUJA, Nigeria (AP) — Five Boko Haram commanders have been released in exchange for the freedom of 82 Chibok schoolgirls, says a Nigerian government official.

The official spoke on condition of anonymity as he was not authorized to speak to reporters on the matter.

The confirmation of the prisoner swap Sunday comes a day after the young women were liberated after more than three years in captivity by the Islamic militants.

There was no immediate comment about the exchange from the Nigerian presidency or Boko Haram, the extremists linked to the Islamic State group. President Muhammadu Buhari said Saturday that some Boko Haram prisoners had been released for the freedom of the schoolgirls, but he did not give any details.

The freed young women were flown Sunday by military helicopters from northeastern Nigeria to Abuja, the capital, where they were expected to meet the president.

“They will face a long and difficult process to rebuild their lives after the indescribable horror and trauma they have suffered at the hands of Boko Haram,” said Pernille Ironside, acting representative of UNICEF Nigeria.

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