According to estimates 200,000 Christians lived in Mosul and its suburbs prior to the offensive launched by IS against Mosul in June. The IS militants gave the Christians an ultimatum either to convert to Islam, pay jaziya or die. As a result nearly all the Christians fled Mosul and its suburbs.
However, only a fraction of these have been accounted for. Where are all the missing Christians? It has been widely speculated that the missing Christians have already been put to sword as was vowed by the IS militants earlier.