Proliferation of arms and ammunition to militias across Iraq has had devastating impacts on civilians, dragging the country into a spiral of insecurity and instability. In the context of the conflict against IS, militias operating under the umbrella of the Popular Mobilization Units (PMU) have extrajudicially executed, tortured and abducted thousands of men and boys. The PMU continue to use a wide range of arms and ammunition to commit or facilitate serious human rights violations and violations of international humanitarian law with impunity. Far stricter controls on the transfer of arms are needed to avoid further serious violations of human rights.