There are two accounts of what took place during the break.[3] According to official reports, a riot broke out at the prison. A prisoner then escaped after seizing weapons from the guards who intervened to stop the riot.[1] The prisoners then captured the prison's armory, which they used to escape. A police officer eyewitness backed this account of events.[2] Brigadier General Saad Maan Ibrahim also attributed the jailbreak to an internal riot.[4]
ISIS, however, claimed the prison break was a coordinated effort between its members on the outside and the inside. Messages posted on ISIS social media said that improvised bombs blew up military and security vehicles near the prison while prisoners on the inside took control of the guard's weapon stock.[3] According to Amaq News Agency, which supports ISIL, ISIL militants broke into the prison with the help of explosives, with the aim of freeing inmates and accessing the prison's weapons stores.[4] Amaq also stated that there were thirty ISIS members among those who escaped, and that about sixty militants were killed by Shi'ite militiamen in ensuing clashes. Oudi Al-Khadran, the mayor of Al Khalis, blamed ISIS for "the killings and the release of ISIS prisoners."[5] Colonel Ahmed al-Timimi, head of the Diyala province security force, also attributed the break to ISIS.[2] Official reports said no external attack had occurred on the prison, although some local sources reported seeing ISIS vehicles attempting to storm it.[1]