Nigeria Chibok girls: Boko Haram video shows captives

The Nigerian Islamist group Boko Haram has released a video showing some of the schoolgirls they abducted from the northern town of Chibok.

Some 50 girls are shown with a gunman who demands the release of fighters in return for the girls, and says some girls died in air strikes.

The government says it is in touch with the militants behind the…