Parents and relatives of missing schoolgirls sit and weeps during a vigil at the school site to mark the 2nd anniversary of their abduction by the Islamists Boko Haram in Chibok, on April 14, 2016. Nigeria's government said it was studying a "proof of life" video showing 15 of the more than 200 schoolgirls abducted by Boko Haram, as parents and their supporters marked the second anniversary of the kidnapping. A total of 276 girls were abducted from the Government Girls Secondary School in Chibok, northeast Nigeria, on April 14, 2014. Fifty-seven escaped in the immediate aftermath. / AFP / STRINGER (Photo credit should read STRINGER/AFP via Getty Images)
