Boko Haram has released a video showing the first pictures of over 200 girls kidnapped from their school in Nigeria a month ago. The rebel group - which has been responsible for a series of atrocities - says the girls have converted to Islam. Boko Haram leader Abubakar Shekau offered to free them in exchange for prisoners held by the government. Al Jazeera's Rawya Rageh reports from Abuja.
