Twenty-one of the more than 200 Chibok schoolgirls kidnapped by Boko Haram insurgents in mid-April 2014 have been released to the Nigerian government, according to government sources quoted by SaharaReporters.

“The sources disclosed that the girls were picked up by military helicopter from Banki area of Borno State where Boko Haram militants dropped them off earlier today,” the report said.

The US-based portal said it could not immediately obtain the names of the released girls.

News Express reports that the Nigerian Government has been negotiating with Boko Haram, which has requested the swapping of the girls, whose abduction caused global outrage, with its detained and imprisoned members.

•Photo shows the Chibok Girls as appeared in a Boko Haram video.