About two-thirds are locked up as “security detainees” without any formal charges in US-run facilities, Lieutenant Colonel Guy Rudisill, the US military spokesman for Iraqi detention operations, told AFP.

The rest are incarcerated in Iraqi-run jails in conditions that fall well below any international standard and are in dire need of reform, said Bakhtiar Amin, Iraq's outgoing human rights minister.

“None of the Iraqi detention centres meet international standards for cleanliness, food and the treatment of prisoners. “Neither are the buildings up to standard. “We have asked for international help.

”Amin acknowledged problems in Iraqi security forces' treatment of detainees following a pair of denunciatory reports by New York based Human Rights Watch and the US State Department since January.

“We are aware of Iraqi security forces' tremendous sacrifices in their struggle against criminality and terrorism. “We cannot ignore the fact that some lose their life in combat, but this does not stop us from criticising the abuses. ”Amin said his ministry would soon deliver a 20-page report on ways to fix the woeful prison system.

There are currently 6,504 inmates in Iraq's 18 prisons, 2,573 of whom have already been sentenced, Amin said, adding that they include both “common-law criminals and terrorists. ”At least 131 of the detainees are women, he said. “In certain places, the situation is deplorable. In others, it is bad, and in others, it is better. ”Not even the International Committee of the Red Cross has visited the Iraqi facilities because they are considered such a high security risk.

US-run jails and detention centres hold a total of 10,708 people, Rudisill said. Of those, 6,054 are in Camp Bucca in southern Iraq - scene of a riot this month in which about 16 people were injured - and another 3,493 are held in the notorious Abu Ghraib prison west of Baghdad, where US troops abused and humiliated naked Iraqi prisoners, provoking international outrage.

About 114 high-level detainees, including ousted dictator Saddam Hussein and several former top aides, are held at Camp Cropper at Baghdad international airport and another 1,047 are locked up at other US military jails. British troops are detaining 27 individuals, Amin added.

“It might not be the most desirable number, but it's a manageable number for us,” said Lieutenant Adam Rondeau. “We're always checking the detention facilities ... to make the conditions better.

”The increase in prisoner numbers resulted from what Rondeau called US military “ongoing operations” before Iraq's January 30 election and growing strength of Iraq military and police forces.

Last November, before US troops started fighting in the city of Fallujah which was then dominated by insurgents, Iraq's total prison population stood at about 5000, according to prison officials at the time.

That figure followed the release of thousands of prisoners since the spring 2004 amid an effort to ease serious over-crowding in the US-run prisons after the Abu Ghraib prison scandal that blotted the reputation of US forces in Iraq. In the aftermath of that scandal, US military officers admitted that many detainees were being held on weak evidence that would not stand up in a regular court of law.

Rudisill said that before the Abu Ghraib scandal, the previous high for detainees was about 8000.