Amnesty said researchers conducted interviews in Jordan and Iraq with former detainees, relatives of current detainees and lawyers involved in detainees' cases in Iraq.

The interviews were conducted last year and this year, Amnesty said at its London headquarters.

"Some of the detainees have been held for over two years without any effective remedy or recourse," Amnesty said in the report. "Others have been released without explanation or apology or reparation after months in detention, victims of a system that is arbitrary and a recipe for abuse."

The U.S. military responded to the report by saying that all detainees are treated according to international conventions and Iraqi law.

A U.S. detention command spokesman, Lieutenant Colonel Guy Rudisill, said, in an e-mailed response to questions, that each detainee is given a form explaining the reasons for his or her imprisonment and the files are reviewed every 90 to 120 days.

The Amnesty report called for an overhaul of the way detainees are treated by the British, American and Iraqi authorities. In particular, Amnesty wants those who detain people in Iraq to ensure that inmates are given due process - a lawyer and an appearance before an impartial court - and to fully investigate any abuse allegations.

"Since Abu Ghraib, the multinational force - and the United States in particular - promised they would put safeguards in place," said an Amnesty spokeswoman, Nicole Choueiry. But the lack of legal safeguards is "still an obstacle to detainees getting and enjoying their human rights," she said.

The report, quoting a U.S. military Web site, said that figures compiled in November showed there were 14,000 detainees in military prisons in Iraq. Last year, the U.S. military said it planned to spend about $50 million to expand Iraqi prison capacity to hold up to 16,000 people.

Notorious photographs from 2003 showing Iraqi inmates being abused led to the convictions of several U.S. soldiers and inquiries by the U.S. authorities into how prisoners were treated.

The Amnesty report urged the British and U.S. governments to publicly declare that torture and degrading treatment of prisoners will not be tolerated, to end indefinite internment of people in Iraq and to conduct impartial, transparent investigations of those accused of mistreating detainees.

The British Defense Ministry said allegations of wrongdoing are taken seriously, and that a police investigation is initiated when there are any grounds that a criminal act might have occurred. It also said that international observers are invited into British detention centers - a policy Amnesty said should be standard for all nations holding prisoners.

Some members of the U.S. Congress raised questions about the payments when it was revealed in December that Iraqi journalists and newspapers were being paid to use articles produced by the military.

Casey said he had not issued an order to halt the payments.

"And, right now, based on the results of the investigation, I do not intend to in the near term," he said.

"However, we will continue to evaluate this over time as the situation on the ground here evolves."

Casey said results of the investigation by Rear Adm. Scott Van Buskirk would be announced in the coming weeks and that some "procedural recommendations" could be made.

Defense Secretary Donald Rumsfeld has said in recent weeks the Pentagon had not done a good job in the information war against enemies like al Qaeda, saying U.S. personnel felt constrained partly due to fear of criticism in the media. The U.S. military has argued it is important to counter what it calls misinformation and propaganda spread by insurgents.

Van Buskirk's inquiry was announced in December after the military confirmed U.S. troops in an "information operations" task force wrote articles with positive messages about the U.S. mission that were translated from English into Arabic and placed in Iraqi newspapers in return for money.

The U.S. command in Iraq at the time said "articles have been accepted and published as a function of buying advertising and opinion/editorial space, as is customary in Iraq."

Some U.S. lawmakers have said the practice could undermine U.S. credibility as American officials try to foster democratic institutions in Iraq and tout its emerging free press.

Rumsfeld said last month that he was mistaken when he stated several days previously that the military had stopped paying Iraqi newspapers to publish pro-American articles.

Copyright © 2006 Reuters Limited

"This news report on a withdrawal of forces within a set timeframe is completely false," Lieutenant Colonel Barry Johnson said of the stories in Britain's Sunday Telegraph and Sunday Mirror, which quoted unnamed senior defense ministry sources.

"As we've said over and over again, any withdrawal will be linked to the ability of the Iraqi security forces to maintain domestic order on behalf of a representative Iraqi government that respects the rights of all its citizens. This is an ongoing assessment and not linked to any timeframe," he said.

UNITY GOVERNMENT

Iraq's Kurdish President Jalal Talabani said he would issue a decree on Sunday to summon a first sitting of the parliament elected in December.

Talabani on Saturday added his voice to pressure from other leaders for Shi'ite Prime Minister Ibrahim al-Jaafari to step aside, saying his resignation would help persuade other parties to form a national unity government that could halt a slide toward civil war.

As at least 14 people were killed in sectarian violence on Saturday, the top U.S. military commander in the Middle East called for a broad coalition Washington hopes can foster stability and allow it to start withdrawing its troops.

The Shi'ite United Alliance, the biggest bloc in the new parliament, nominated Jaafari to keep his job despite security and economic difficulties and criticism of his handling of violence that has killed more than 500 people since the destruction of a major Shi'ite shrine in Samarra on February 22.

But smaller factions are refusing to join a coalition he leads and rival Shi'ite leaders are considering putting up a new nominee, political sources say. Parliament is likely to sit around next Sunday, government sources say, but forming a government may take much longer.

The premier must be confirmed by a two-thirds majority.

General John Abizaid, head of U.S. Central Command, met both Talabani and Jaafari in Baghdad: "The government of national unity must be formed to bring the country together," he said.

There are about 135,000 U.S. soldiers and Marines and about 8,500 British troops in Iraq. The full U.S.-led coalition numbers around 160,000. Italy, with the fourth largest contingent in Iraq, has said it plans to pull out this year.

U.S. and British troops have trained 230,000 Iraqis to take on roles in the police force and Iraqi army, but both are currently incapable of securing the country on their own.

Talabani and Shi'ite Interior Minister Bayan Jabor have called for sectarian and ethnic militias to join the U.S.-trained security forces, something U.S. officials in Baghdad have long been urging.

Government leaders, including Talabani and Jabor, are in parties which have justified maintaining their own militia forces, however, and Jabor set no timetable for any change.

"There is no reasonable justification for any fear of the militias at the present time," Jabor said.

Sunni leaders have accused the government of condoning death squads targeting minority Sunnis and operating from inside the Shi'ite-controlled Interior Ministry. In the north, Sunni Arabs complain of the power of Kurdish peshmerga militias.

Militia leaders deny condoning any such violence.