Linda Boyle (left) and Lyn Coleman hold a photo of their children, who were kidnapped in Afghanistan in 2012. Caitlan Coleman, an American married to Canadian Joshua Boyle, was pregnant when the couple was abducted. Bill Gorman/AP hide caption

itoggle caption Bill Gorman/AP

Mourners pray during a ceremony for Jordanian pilot Muath al-Kaseasbeh, who was killed by the Islamic State after he was captured in December. At Wednesday's service, which took place in the city of Karak, mourners called for the destruction of ISIS. Khalil Mazraawi/AFP/Getty hide caption

itoggle caption Khalil Mazraawi/AFP/Getty

A frame grab from a video released by the Islamic State shows an IS militant holding a knife before purportedly executing British aid worker David Cawthorne Haines. Islamic State Video/EPA /LANDOV hide caption

itoggle caption Islamic State Video/EPA /LANDOV

Thursday night in Midland City, Ala., there was a candlelight vigil for bus driver Charles Poland, who was killed Tuesday before a gunman snatched a 5-year-old boy — who is being held captive in an underground bunker. Philip Sears /Reuters /Landov hide caption

itoggle caption Philip Sears /Reuters /Landov

Islamist militants raided the In Amenas natural gas field (pictured) in Algeria on Wednesday and took several hostages. BP/AP hide caption

itoggle caption BP/AP