The bodies were discovered near the town of Rutba, 370 kilometers west of Baghdad, in the mainly Sunni Arab desert province of Anbar. The area is a stronghold of the insurgency against the Shi'ite and Kurdish-led government.
Police say the bodies all had their hands tied and that the men appeared to have been killed three days ago.
The identities of the victims is unclear. Insurgents in the area in the past have killed Shi'ites traveling to Jordan and Syria, as well as members of Iraq's security forces.