Iraqis take part in a candlelight vigil at the shrine of Imam Ali in Iraq's central city of Najaf on February 27, 2015, in memory of Muslim and Christian victims killed by the Islamic State (IS) group. IS is accused of multiple abuses against minorities in the areas under its control in Iraq, Syria and elsewhere. Last week, a video emerged showing its fighters in Libya beheading 21 Christians, most of them Egyptian Copts. AFP PHOTO / HAIDAR HAMDANI        (Photo credit should read HAIDAR HAMDANI/AFP/Getty Images)