Video appears to show #BringBackOurGirls group abducted by Boko Haram in 2014

A video has surfaced which appears to show some of Nigeria's kidnapped Chibok girls who have not been heard from since the mass abduction by the Islamic extremist group Boko Haram two years ago.

CNN showed video, believed to be made in December, of girls wearing the Islamic hijab covering and of one mother reaching out to a computer screen as she recognises her daughter.