Following Thursday’s release of 21 out of the 218 Chibok school girls abducted by the terrorist Boko Haram group in Nigeria, questions about how they were freed have continued to become glaring.

A security official who confirmed with the BBC said that several top-level Boko Haram detainees were taken to a meeting point close to the Cameroon border.

Some of the 21 released Chibok girls are shown Thursday in Banki, Nigeria, near the Cameroon border, in a photo. CNN.

Under the supervision of the ICRC, the girls were then released with allegations that some militants were handed over, a claim which the presidency has debunked.

The minister of Information and Culture, Alhaji Lai Mohammed, in Abuja at a world press conference held on the latest development on the abducted Chibok Girls, disclosed that the release of the 21 Chibok school girls was never based on swap but on confidence building.

The students were then transported to the city of Maiduguri and placed under the supervision of the security forces.

According to the security official, most of the young women have babies.

Just last month, the Nigerian government announced that several round of talks with Boko Haram had broken down, but with this release, they have shown that those kidnapped can be released through intermediaries.

Up to now there had only been one confirmed release of a student kidnapped from Chibok.

In May, a 19-year-old woman was found by an army-backed vigilante group.

After that it was believed that 218 students were still missing. More than 50 managed to escape on the day they were captured.