Graphic accounts by Iraqi prisoners of abuse at the hands of US soldiers have been published in a US newspaper, with fresh images depicting ill-treatment.
The Washington Post says it has seen hundreds of videos and photos which show previously unseen abusive methods used at Baghdad's Abu Ghraib jail.
In sworn statements, detainees said they were beaten, sexually humiliated and force-fed pork and alcohol.
The revelations came as the US began freeing 472 detainees from the prison.
The new photos include one of a prisoner being menaced by a soldier with a dog.
In other abuses depicted in the latest pictures:
A naked prisoner who appears to be covered in excrement is paraded down a corridor
A hooded detainee is pictured in a state of collapse
A US soldier appears to be raining blows down on detainees sprawled on the floor.
The Washington Post report also describes a video clip which shows an inmate shackled to a door.
He repeatedly slams his head into the metal, leaving streaks of blood, before he ultimately collapses at the feet of the cameraman.
Fresh fighting
As the latest reports were published, US forces in Iraq began freeing 472 detainees from Abu Ghraib jail.
Six buses filled with Iraqis drove away from the prison gates in the first phase of the latest releases.
In other developments in Iraq on Friday:
Coalition forces are holding two people in connection with the beheading of US businessman Nicholas Berg, the US military said. Four people were detained two days ago, but two had since been released.
US troops fought renewed battles with rebels loyal to radical Shia cleric Moqtada Sadr in the holy city of Karbala. Several people are killed including an al-Jazeera television employee
US forces arrested dozens of Mr Sadr's supporters in the northern city of Kirkuk, Iraqi police told the AFP news agency
In the city of Baquba, north of Baghdad, four Iraqi security force members were killed when gunmen opened fire on a checkpoint
Spanish radio journalist Fran Sevilla was taken hostage in Najaf by Mr Sadr's rebels, Spanish national radio reported. The station later reported that he had been released
A body believed to be that of Italian hostage Fabio Quattrocchi, killed by his captors on 14 April, has been handed over to the Italian Red Cross in Iraq, the organisation said.
The BBC's Justin Webb in Washington says the Washington Post appears to have gained access to photos and video clips recently shown to members of Congress by the Pentagon but not made public.
Our correspondent says the pictures do nothing to assist in the search for those ultimately responsible for the abuse - but they will do plenty to darken the already depressed mood in Washington about the conduct of the war and its future outcome.
Humiliated
In the accompanying accounts, several Iraqi prisoners are quoted giving graphic details of abuse by US soldiers.
One detainee, named in the report as Ameen Saeed al-Sheik, said he was asked by a soldier whether he believed in anything.
"I said to him, 'I believe in Allah.' So he said, 'But I believe in torture and I will torture you.'"
He said one soldier struck his broken leg and ordered him to curse Islam.
"Because they started to hit my broken leg, I curse my religion," the paper quoted him as saying. "They ordered me to thank Jesus I'm alive."
Other detainees said they were stripped on arrival at the prison, forced to wear women's underwear and repeatedly humiliated in front of each other and American soldiers.
Courts martial
The Washington Post said eight of the detainees identified one soldier, Specialist Charles Graner, who is facing charges of maltreatment, indecent acts and obstruction of justice.
One detainee accused him of repeatedly throwing prisoners' meals into the toilets and saying, "Eat it."
Spc Graner has previously said he was following instructions given to him by military intelligence officials.
The Washington Post said it had tried to contact Spc Graner's lawyer, but he had not returned the paper's calls.
Spc Graner is one of seven US soldiers who have been ordered to stand trial on charges of abusing prisoners at Abu Ghraib jail.
One, Jeremy Sivits, has already pleaded guilty at a court martial to four counts including maltreatment of detainees. He was jailed for a year, demoted and discharged from service.
Following the abuse scandal in Iraq, new questions have been raised over the treatment of inmates held by the US at Guantanamo Bay in Cuba.
US defence officials say that in late 2002, Defence Secretary Donald Rumsfeld approved a request by interrogators to use some techniques that went beyond normal military doctrine.
However, they add that the changes were later scaled back after objections from military lawyers.
http://news.bbc.co.uk/2/hi/americas/3734531.stm