· Account belies picture painted by White House

An official assessment drawn up by the US foreign aid agency depicts the security situation in Iraq as dire, amounting to a "social breakdown" in which criminals have "almost free rein".

The "conflict assessment" is an attachment to an invitation to contractors to bid on a project rehabilitating Iraqi cities published earlier this month by the US Agency for International Development (USAid).

The picture it paints is not only darker than the optimistic accounts from the White House and the Pentagon, it also gives a more complex profile of the insurgency than the straightforward "rejectionists, Saddamists and terrorists" described by George Bush.

The USAid analysis talks of an "internecine conflict" involving religious, ethnic, criminal and tribal groups. "It is increasingly common for tribesmen to 'turn in' to the authorities enemies as insurgents - this as a form of tribal revenge," the paper says, casting doubt on the efficacy of counter-insurgent sweeps by coalition and Iraqi forces.

Meanwhile, foreign jihadist groups are growing in strength, the report said.

"External fighters and organisations such as al-Qaida and the Iraqi offshoot led by Abu Musab al-Zarqawi are gaining in number and notoriety as significant actors," USAid's assessment said. "Recruitment into the ranks of these organisations takes place throughout the Sunni Muslim world, with most suicide bombers coming from Saudi Arabia and other countries in the region."

The assessment conflicted sharply with recent Pentagon claims that Zarqawi's group was in "disarray".

The USAid document was attached to project documents for the Focused Stabilisation in Strategic Cities Initiative, a $1.3bn (£740m) project to curb violence in cities such as Baghdad, Basra, Mosul, Kirkuk and Najaf, through job creation and investment in local communities.

The paper, whose existence was first reported by the Washington Post, argues that insurgent attacks "significantly damage the country's infrastructure and cause a tide of adverse economic and social effects that ripple across Iraq".

"In the social breakdown that has accompanied the defeat of Saddam Hussein's regime criminal elements within Iraqi society have had almost free rein," the document says. "In the absence of an effective police force capable of ensuring public safety, criminal elements flourish ... Baghdad is reportedly divided into zones controlled by organised criminal groups-clans."

The lawlessness has had an impact on basic freedoms, USAid argues, particularly in the south, where "social liberties have been curtailed dramatically by roving bands of self-appointed religious-moral police". USAid officials did not respond to calls seeking comment yesterday.

Judith Yaphe, a former CIA expert on Iraq now teaching at the National Defence University in Washington, said while the administration's pronouncements on security were rosy, the USAid version was pessimistic. "It's a very difficult environment, but if I read this right, they are saying there is violence everywhere and I don't think it's true," Ms Yaphe said. She said USAid could have published the document to pressure the White House to increase its funding. The administration does not intend to request more reconstruction funds after the end of this year.