A suicide bomber has attacked government-backed Sunni militiamen as they lined up to be paid on Baghdad's southwestern outskirts, killing at least 43 and wounding 41, security sources said.
The blast happened outside an Iraqi military base in the Sunni district of Radwaniya. The suicide bomber blew himself up among "Sahwa" militiamen, Sunni fighters who once allied with al Qaeda but turned on the militant group in 2006 to 2007, helping US forces turn the tide in the war.
All of the dead were Sahwa an Interior Ministry source said.
There has been a series of attacks against Sahwa leaders in Sunni areas around Baghdad in recent months, many attributed to acts of revenge by former fellow insurgents, or al Qaeda. Some have been blamed on long-running blood feuds between families.
The sectarian war between once dominant Sunnis and majority Shi'ites that broke out after the 2003 US-led invasion has largely subsided but a stubborn Sunni Islamist insurgency persists.
The US military has increasingly been taking a backseat role since pulling out of Iraqi urban centres in June last year and US troops will end combat operations on August 31 ahead of a full withdrawal next year.