Twin bombings killed nine people and wounded 21 on Friday in Ramadi in Iraq's western province of Anbar, most of them anti-Al-Qaeda militiamen, a security official said.
A bomb placed in the car of an officer of the Sahwa (militia) exploded before a second one, placed on the roadside, detonated among a group of people, Colonel Jubeir Nayef said.
"Nine people died and 21 were wounded, mostly members of Sahwa, when two bombs went off in Ramadi," the main town in Anbar province west of Baghdad, the officer, himself a member of the militia, said.
Doctor Ahmad al-Aani, who works at Ramadi general hospital, confirmed the toll.
The Sahwa (Arabic for "awakening") militias were formed in 2006 at the height of Iraq's sectarian conflict to combat Al-Qaeda militants, and were led by tribal leaders in majority-Sunni areas of the country.
Since then, the militia has continued to fight Al-Qaeda by setting up road blocks and patrolling areas its fighters are known to operate in, but has itself been a target for the militants.
The Ramadi bombings came a day after a series of attacks mostly targeting cafes in and around Baghdad killed 17 people.
Iraq has seen an rise in violence since the beginning of the year, coinciding with protests among the country's Sunni Arab minority against what demonstrators see as discrimination by the Shiite-led authorities.