Authorized by President George W. Bush in March 2002 as part of a policy of "regime change" in Iraq, the Scorpions were made made up mostly of exiles recruited by the Kurds who were sent to Iraqi cities including Baghdad, Fallujah and Qaim to give the impression that a rebellion was under way, current and former US intelligence officials told The Washington Post.

Trained with millions of dollars to conduct light sabotage, the covert unit was even given former Soviet Hind helicopters, but most of its missions were delayed and it ended up merely "sowing confusion", by painting graffiti on walls or cutting electricity.

The speed of the US invasion of Iraq in March 2003, intelligence officials said, negated most of the Scorpions' missions.

So after the war, the CIA used the Scorpions to try to infiltrate the insurgency, to act as translators, to help out in interrogations and, from time to time, to do "the dirty work," one official said.

In one case, members of the Scorpions wearing masks and carrying clubs and pipes beat up an Iraqi general in the presence of CIA and US military personnel, according to documents reviewed by The Washington Post.

The CIA's control over the Scorpions weakened as chaos grew in Iraq, another intelligence official said.

"Even though they were set up by us, they weren't well supervised," said the official.

The Scorpion teams, who after the war wore civilian clothes and traveled in civilian vehicles, were mistaken for insurgents and attacked by US soldiers, the officials said.