Boko Haram is a militant Islamic group that has existed for more than a decade in Nigeria, but it has become increasingly violent since an internal leadership change in 2009.
Nigerian President Muhammadu Buhari claims that he defeated Boko Haram, but the level of attacks on towns and refugee camps continue. The 2014 kidnapping in Chibok has caused tension as both government and military officials have been criticized for how they handled the incident and for their failure to bring the girls home.
The new images offer the first glimpse of the girls since a video released in May 2014. Boko Haram militants attacked the government boarding school on April 14, 2014, resulting in 276 schoolgirls being abducted, with 57 students managing to escape.
The horrific kidnapping prompted the global social media campaign #BringBackOurGirls, which was joined by First Lady Michelle Obama, Hillary Clinton and many celebrities.