The skull of a decapitated man is seen at a mass grave in the recently retaken town of Damasak, Nigeria, March 20, 2015. Soldiers from Niger and Chad who liberated the Nigerian town of Damasak from Boko Haram militants discovered the bodies of at least 70 people, many with their throats slit, scattered under a bridge, a Reuters witness said. (Photo by Emmanuel Braun/Reuters)
