ABUJA, Nigeria — U.S. reconnaissance aircraft were flying over Nigeria on Tuesday in the search for nearly 300 kidnapped schoolgirls, a day after the Boko Haram militant group released the first evidence that at least some of them are still alive and demanded that jailed fighters be swapped for their freedom.
A Nigerian government official said "all options" were open in the effort to free the girls, who were shown fearful, huddled and dressed in gray Islamic veils as they sang Koranic verses under the guns of their captors in a video released Monday.
The footage was verified as authentic by Nigerian authorities, who said 54 of the girls had been identified by relatives, teachers and classmates who watched the video late Tuesday.
The abduction has spurred a global movement to secure the girls' release amid fears they would be sold into slavery, married off to fighters or worse after a series of threats by Boko Haram leader Abubakar Shekau.
Protesters marched through the streets of the capital, Abuja, Tuesday to demand more government action to find and free the girls, who were seized from their school on April 15.
A U.S. reconnaissance mission was being carried out by a manned MC-12 surveillance aircraft based in Niger, according to senior U.S. defense officials in Washington. In addition to the turboprop model that has seen heavy use in Afghanistan, U.S. officials were also considering the use of drones.