Boko Haram has released a video demanding the release of all militants held by the government in exchange for the return of about 220 still-missing Nigerian girls, many of whom appear in the video praying and wearing full-length hijabs, according to Agence-France Presse.

AFP, which obtained the video, reports that it features the Islamist militant leader Abubakar Shekau speaking for about 17 minutes before showing footage of some of the missing girls praying in an unknown location. In the video, Shekau claims that those abducted have converted to Islam. 

The BBC adds that three girls speak during the video. Two say they were Christians who have converted to Islam, and one simply described herself as a Muslim. The three appear calm and one said they have not been harmed by the violent abductors. 

Boko Haram first claimed responsibility for kidnapping nearly 300 Chibok schoolgirls in mid-April in a video made public about one week ago. 

Nigerians and members of the international community sympathetic to their plight are frustrated by the government's lack of action, a critique bolstered by a recent Amnesty International report claiming military officials had advance warning of the attack that led to the kidnapping, but failed to act to protect the schoolgirls. And the government has been refusing many offers by the U.S. and other countries to help search for the missing.

Still, Nigerian President Goodluck Jonathan said on Sunday that he will accept help from Israel and that he is "very optimistic that with the entire international community deploying its considerable military and intelligence-gathering skills and assets in support of Nigeria's efforts … success will soon be achieved."