During the Syrian Civil War and the spillover into Iraq, persecution of Christians by ISIL and other militant groups has been ongoing. The Fall of Mosul and the Assyrian town of Qaraqosh in the 2014 ISIL advance in Iraq led to an estimated 100,000 Assyrian Christian civilians being displaced. After the fall of Mosul, ISIL demanded Assyrian Christians in the city to convert to Islam, pay tribute, or face execution. ISIL begun marking homes of Christian residents with the letter "nūn" for "Nassarah" ("Christian"). Thousands of Christians, Yazidis (the latter whom were given only the choice of conversion or death) and other, mostly Shi'a Muslims (whom ISIL consider to be apostates) have abandoned their homes and land. The destruction of cultural heritage by ISIL has included the Mosque of the Prophet Jonah, revered in all Abrahamic faiths.