Islamist extremist sect Boko Haram Monday released a video demanding the release of all imprisoned insurgents in Nigeria in exchange for the school girls abducted by the group four weeks ago.
The video, obtained by news agency Agence France Presse, showed about 130 veiled, praying girls.
Boko Haram leader Abubakar Shekau said the teenagers had converted to Islam.
The teenagers were abducted on April 14 from a boarding school in the town of Chibok, about 130 kilometres from Borno state capital Maiduguri.
Nigeria’s government had been unable to find any trace of the girls up until now.
The kidnapping caused an international outcry, with the United States, Britain, China, France and Canada pledging their support in the search for the girls.