Ever since Iraq's Popular Mobilization Units (PMU) was founded three days after the Islamic State (IS) took control of Mosul on June 10, 2014, the PMU has been controversial. It has participated in several battles that reportedly involved human rights violations such as the Tikrit liberation battle in April 2015 and the Fallujah liberation battle just days ago.

Because of the alleged violations, Sunni political parties have called on the mostly Shiite PMU not to engage in the battle to liberate Mosul. But for the PMU, which supports the Iraqi security forces, the Mosul battle is key. PMU leaders believe the battles they have fought so far have been leading to Mosul, which is of great importance to IS and serves as the capital of its caliphate in Iraq.

Despite Sunni politicians' fears and the ongoing effort to keep the PMU out of the battle, some PMU commanders insist on participating.

Hadi al-Ameri, leader of the Badr Organization, a PMU faction, said in a June 25 press statement, “The PMU will take part in the liberation of Mosul, against the will of the politicians who oppose this,” in reference to some Sunni politicians from Mosul.