The Islamist militant group Boko Haram has released a video it claims shows dozens of missing schoolgirls abducted last month in northern Nigeria.
The 17-minute video shows about 100 of the girls dressed in black and gray full-length hijabs, sitting in an undisclosed rural area, reciting Muslim scriptures and holding their hands for prayers.
The group's leader, Abubakar Shekau, speaks on the video obtained by the French news agency AFP for 17 minutes before showing what he said were the girls, in Muslim dress and praying in an undisclosed rural location.
The White House says it has seen the video and has no reason to question its authenticity. Spokesman Jay Carney said U.S. intelligence experts are carefully looking at the video for clues that could help find the girls. He also said the Untied States is providing intelligence, surveillance and reconnaissance support to Nigeria's government.
"As you know, President Obama has directed his team to do everything it can to support the Nigerian government's efforts to find and free these girls. I can report to you that our interdisciplinary team with representatives from the State Department, Department of Defense, the FBI and others is up and running now in our Embassy in Nigeria, helping to support the Nigerian government by providing military and law enforcement assistance as well as intelligence, surveillance and reconnaissance support," said Carney.
"Our intelligence experts are combing through every detail of the video for clues that might help in ongoing efforts to secure the release of the girls," U.S. State Department spokeswoman Jen Psaki told reporters Monday. After acknowledging that "Nigeria is in the lead" in the effort to find the girls and that the U.S. was playing a support role, Psaki dismissed Shekau's demand, saying "the United States' policy is to deny kidnappers the benefits of their criminal acts -- including ransoms or concessions."
In comments to the French News Agency, Nigerian Interior Minister Abba Moro said the government would not consider a swap of jailed militants for the schoolgirls.
But the Director General of Nigeria's National Orientation Agency, Mike Omeri, said officials are studying the situation, and all options remain open to free the missing girls.
Nigerian authorities are holding hundreds of suspected Boko Haram militants in jail.
A total of 276 girls were abducted on April 14 from the northeastern town of Chibok, in Borno state, which has a sizeable Christian community. About 223 are still missing.
The footage shows about 130 girls in black and grey full-length hijabs sitting on scrubland near trees, reciting the first chapter of the Muslim holy book, the Quran, and holding their palms upwards in prayer.
In the video, three of the girls are interviewed. Two of the girls said they were Christian and had converted, while the other one said she was Muslim. Most of the group remained seated. The girls appeared calm and one said that they had not been harmed.
There was no indication of when the video was taken, although the quality is better than on previous occasions and at one point an armed man is seen in the shot with a hand-held video camera.
Boko Haram has been waging an increasingly deadly insurgency in Nigeria's mainly Muslim north since 2009, attacking schools teaching a "Western" curriculum, churches and government targets.
Civilians, though, have borne the brunt of recent violence, with more than 1,500 killed this year alone while tens of thousands have been displaced after their homes and businesses were razed.