The death toll from a suicide attack at a military base near Baghdad has increased to at least 43.

A suicide bomber on December 24 blew himself up among a group of pro-government Sunni militiamen who had gathered at a base in the town of Madain to receive their salaries. 

Officials originally said at least 22 Sunni militia fighters were killed.

At least 61 were wounded in one of the deadliest attacks in months.

The United States confirmed the dead were anti-Islamic State (IS) fighters.

The militias, known as the Awakening Councils, are comprised of Sunni fighters who had joined U.S. troops to battle Al-Qaeda during the height of Iraq's insurgency in 2007 and 2008. 

Those Sunni militia fighters are now battling IS militants. 

No one has claimed responsibility for the bombing.

Based on reporting by dpa, AP, AFP