Sources in Nigeria have been giving the our correspondents more details about how the prisoner swap was organised to secure the release of the Chibok girls.
Nigeria’s presidential spokesman said the Swiss government and International Committee of the Red Cross (ICRC) were behind the negotiations.
Nigeria news website Sahara Reporters, which first reported the news today about the release of the Chibok girls, has been tweeting more details a prisoner swap that secured their freedom.
The details are yet to be confirmed, but the site says 18 of the girls have babies and they were swapped for four high-profile Boko Haram commanders:
FLASH: 21 freed Chibok girls swapped with four four high profile Boko Haram militants
FLASH: #bringbackourgirls 18 of the 21 freed Chibok girls are nursing mothers
It also reports that the girls are on their way to the capital, Abuja:
FLASH: 21 Chibok girls are now on their way to Abuja by air, they left Nigeria Airforce base in Maiduguri for Abuja at 9:15 am Nigeria time
It seems that it was the ICRC that helped in the physical swap.
One AFP source said the girls were brought in Red Cross vehicles to Kumshe, which is about 15km (nine miles) from a military base in Banki, a town that borders Cameroon.
“The four Boko Haram militants were brought to Banki from Maiduguri in a military helicopter from where they were driven to Kumshe in ICRC vehicles,” the source said.
Another source added: “The 21 girls arrived [in] Banki around 3:00 (0:200 GMT) where they found a military helicopter waiting.”
