Images of US soldiers allegedly abusing Iraqi prisoners at a notorious jail near Baghdad have sparked shock and anger.
The CBS footage showed graphic images of the abuse of Iraqi prisoners (AP Photo/Courtesy of The New Yorker)
Politicians in the US, Britain and the Middle East expressed disgust at the images, broadcast on US television, and called for those responsible to face justice.
CBS News said it delayed the broadcast for two weeks after a request from the Pentagon due to the tensions in Iraq.
Last month, the US army suspended 17 soldiers over alleged prisoner abuses.
Elsewhere in Iraq, US marines have begun withdrawing from the Iraqi city of Falluja after a month of bloody clashes with rebels.
Two battalions have been pulling back from front-line positions and are set to move further out during the day.
A new Iraqi force, led by one of Saddam Hussein's former generals, is expected to move into the city while the US maintains a presence outside the flashpoint city.
Six soldiers - including a brigadier general - are facing court martial in Iraq, and a possible prison term over the PoW pictures.
A spokesman for British Prime Minister Tony Blair said he was "appalled" and described the incident as regrettable.
"Nobody underestimates how wrong this is, but these actions are not representative of the 150,000 coalition soldiers in Iraq. We shouldn't judge the actions of coalition soldiers as a whole by the actions of a few," he said.
Abu Ghraib prison was much feared in Saddam Hussein's era
US Republican congressman, Jim Leach - who had opposed the war - said: "The US has historically prided itself on treating prisoners of war with decency and respect.
"This has to be investigated and accountability obtained within the American military justice system."
Adnan Al-Pachachi, a member of the Iraqi Governing Council, said it would create a great deal of anger and discontent among Iraqis already concerned about security in the country.
But he rejected a comparison with the treatment of prisoners at Abu Ghraib prison near Baghdad during the days of Saddam Hussein.
"I don't think you can compare the two. Saddam Hussein's prisoners were not only tortured but executed. It was much worse than what is there now."
The graphic images include one of a hooded and naked prisoner standing on a box with wires attached to his genitals. CBS said the prisoner was told that if he fell off the box, he would be electrocuted.
Another shows naked prisoners being forced to simulate sex acts. In another, a female soldier, with a cigarette in her mouth, simulates holding a gun and pointing at a naked Iraqi's genitals.
CBS's flagship 60 Minutes programme said it had been pressured by the Pentagon not to show the images, until the photos started circulating elsewhere.
"The Pentagon was really very concerned about broadcasting the pictures, and I think they had good reason," said 60 Minute executive producer Jeff Fager.
"The idea that there are hostages being held in Iraq concerned us quite a bit in terms of broadcasting them. It wouldn't take long to get on Al-Jazeera at all."
Mr Fager told the BBC's Today programme the pictures were initially brought to the attention of US military in Iraq, and formed the centrepiece of proceedings against the soldiers.
One of the suspended soldiers, Staff Sergeant Chip Frederick, said the way the army ran the prison had led to the abuse.
"We had no support, no training whatsoever. And I kept asking my chain of command for certain things... like rules and regulations," he told CBS. "It just wasn't happening."
He said he did not see a copy of the Geneva Convention rules for handling prisoners of war until after he was charged.
Deputy head of coalition forces in Iraq, Brig Gen Mark Kimmitt told CBS the army was "appalled" by the behaviour of its soldiers.
He said the suspected abusers "let their fellow soldiers down".
Meanwhile, a new opinion poll for the New York Times and CBS News suggested dwindling support among Americans for the invasion and occupation of Iraq.
Only 47% of 1,042 Americans questioned believed invading Iraq was the right thing to do, the lowest support recorded in the polls since the war began.