Baghdad: The gunmen who massacred 25 people from Iraqi families linked to an anti-Qaeda militia posed as American soldiers in a bid to reassure villagers before shooting them, a security spokesman said on Sunday.
Twenty-five men have been arrested in connection with the rampage in the village of Sufia on the southern outskirts of Baghdad that began just before midnight Friday and continued for at least two hours.
Iraqi officials have blamed al Qaeda for the killings.
"They wore American military uniforms, two or three of them spoke English, to give the impression that they were American forces," said Major General Qassim Atta, the spokesman for the Iraqi security forces` Baghdad operations.
Atta added that they carried weapons bearing laser pointers, a familiar sight among US troops in Iraq.
A medical official at Al-Yarmuk hospital in west Baghdad who had seen police reports of the violence confirmed that some of the killers wore clothing similar to US military uniforms.
Five women were among the 25 killed, all linked to the Sahwa (Awakening) movement, known as the "Sons of Iraq" by the US Army, which joined American and Iraqi forces in 2006 and 2007 to fight against al Qaeda and its supporters, leading to a dramatic fall in violence across the country.
The victims were all tied up and shot either in the head or in the chest. Seven other civilians discovered handcuffed in the village were freed.
Atta said that 25 people have been arrested in connection with the attacks, the worst against anti-Qaeda fighters since at least November 16 when 13 members of a tribe opposed to the jihadists were murdered west of Baghdad.
"Several of them confessed, and we are sure they are al Qaeda terrorists," Atta said.
The brutal killings come as Iraq`s political parties negotiate to form a government, nearly a month after a general election.
Security officials have warned that a protracted period of coalition building could give insurgents an opportunity to further destabilise Iraq.