LAGOS, May 7 (Xinhua) -- Eighty-two schoolgirls abducted by the Boko Haram terrorist group have been released in exchange for the freedom of some Boko Haram suspects, the government said Saturday.

"President (Muhammadu) Buhari is pleased to announce that negotiations to release more of the Chibok girls have borne fruit with the release of 82 more girls today after months of patient negotiations. Our security agencies have taken back these abducted girls in exchange for some Boko Haram suspects held by the authorities," said presidential spokesman Garba Shehu on Saturday.

"The girls are due tomorrow (Sunday) in Abuja to be received by the president. The president expressed his deep gratitude to security agencies, the military, the government of Switzerland, the Red Cross, local and international NGOs for the success of the operation."

Some 276 girls were seized by Boko Haram fighters who stormed their dormitories in April 2014 in Chibok town of Borno State in northeastern Nigeria.

Over the following two years, 57 girls managed to escape. The rest of them had been missing until 21 girls were freed by their abductors in October 2016.

Nigeria's northeastern region has been a Boko Haram stronghold. The group has been blamed for the deaths of more than 20,000 people and displacing of 2.3 million others in Nigeria since their insurgency started in 2009.