MAIDUGURI (Reuters) - A video circulating on social media on Thursday purportedly showed Islamist militant group Boko Haram with some of the hundreds of schoolboys kidnapped last week in northwest Nigeria. The video, featuring Boko Haram’s emblem, showed a group of boys in a wood begging security forces to leave the area. Reuters was not able to immediately verify the authenticity of the footage, the boys shown or who released it. A spokesman for Nigerian President Muhammadu Buhari did not immediately respond to a call and messages regarding the video. The group claimed responsibility for the Dec. 11 kidnappings earlier this week, but previously had shown no proof. If its claims are true, Boko Haram’s involvement in northwestern Katsina state marks a geographical expansion in its activities.