The militiamen, members of the Sahwa group, were killed outside the town of Tuz Khormato, about 210km north of Baghdad. Police said they were lured to a checkpoint where gunmen overpowered them, tied them up and executed each with a gunshot to the head.
Sahwa joined forces with US troops to fight al-Qaeda during the Iraq war. Ever since then, it has been a target for Sunni insurgents who consider its members to be traitors.
Elsewhere, in a northern suburb of Baghdad, a car bomb killed one civilian bystander and wounded three policemen when it hit a police convoy, police said. Hospital officials confirmed the casualties. All officials spoke on condition of anonymity because they are not authorised to brief reporters.
The killings happened hours before tens of thousands of Sunnis rallied in several cities protesting against perceived discrimination by the government of Prime Minister Nouri al-Maliki.
They renewed threats to march on the capital if the government continues to ignore their demands, echoing comments a prominent sheik, Ahmed Abu Risha, made to The Associated Press earlier this week.
For the past two months, Sunni Muslims have been protesting what they describe as unfair treatment by the country's Shiite-led government, extending concerns over rising sectarian tension in the country.
Baghdad: Attackers disguised in military uniforms killed seven anti-al Qaeda militiamen in Iraq on Friday as anti-government protests once again raged in Iraq's Sunni provinces.
First Published: Saturday, February 23, 2013, 00:33