Prominent world leaders, such as British PM David Cameron, German chancellor Angela Merkel and Pope Benedict XVII have made similar claims about Christians in the middle east.
ISIS have also destroyed churches and ancient Christian artefacts in Syria and Iraq.
But Sufi and Shiite Muslims have also been killed by ISIS. The Assad regime has deliberately targeted Sunni Muslims in Syria.
A Pew Centre study on religious hostility found that Christians and Muslims faced the most harrassment by government or social groups.
Christians were harrassed in 102 of the 198 countries included in the study (52%), while Muslims were harassed in 99 countries (50%), the study found.