Shia Muslims have been killed in large numbers by ISIL. On 12 June 2014, ISIL killed 1,700 unarmed Shia Iraqi Army cadet recruits in the Camp Speicher massacre. ISIL has also targeted Shia prisoners. According to witnesses, after the militant group took the city of Mosul, they divided the Sunni prisoners from the Shia prisoners. Up to 670 Shia prisoners were then taken to another location and executed. Kurdish officials in Erbil reported on the incident of Sunni and Shia prisoners being separated and Shia prisoners being killed after the Mosul prison fell to ISIL.
Amnesty International has held ISIL responsible for the ethnic cleansing of ethnic and religious minority groups in northern Iraq (Christians and Yezidis) on a "historic scale", putting entire communities "at risk of being wiped off the map of Iraq". In a special report released on 2 September 2014, it described how ISIL had "systematically targeted non-Sunni Muslim communities, killing or abducting hundreds, possibly thousands, of individuals and forcing more than tens of thousands of Shias, Sunnis, along with other minorities to flee the areas it has captured since 10 June 2014". The most targeted Shia groups in Nineveh Governorate were Shia Turkmens and Shabak, who have lived together for centuries in Nineveh, large parts of which came under ISIL's control from mid-2014 to late 2017.