Iran-backed Popular Mobilisation Units fought alongside government forces in the fight against Daesh. Many of its fighters have now abandoned arms to take part in Iraq's political process.
Iraq's Popular Mobilisation Units (PMUs) — also known as Hashd al Shaabi — make up the largest institutional grouping outside direct government control.
The group's fighters were key allies in the Iraqi government's fight against Daesh.
After Daesh was defeated, many PMU members abandoned their arms and stood for office in last month's parliamentary elections in Iraq.
Most PMU are Shia Muslims, and they have the support of Iran.
TRT World's Ash Gallagher has this special report from Baghdad on the influence of Iran in Iraq and the role of the PMU.