Desperate to limit the damage from the Abu Ghraib prison scandal, the US military has launched something of a charm offensive surrounding their detention centres.

They face an uphill struggle.

The photographs showing Iraqi prisoners being humiliated at Baghdad's Abu Ghraib have badly damaged the reputation of the world's largest army here amid growing opposition to the occupation.

A recent poll showed 80 percent of Iraqis mistrust the US-led coalition.

Camp War Horse, a 1,500 square metre (more than 16,000 square foot) complex on a windswept strip of desert, is the first port of call for "anti-Iraqi forces" arrested by the Americans in Diyala province, north of Baghdad.

Detainees are interrogated for between three and seven days.

Then they are either sent home, or, if something turns up the US military does not like, handed over to Iraqi police or transferred to the US 1st Infantry Division, based in Saddam Hussein's home town of Tikrit.

Clutches of former prisoners interviewed by AFP have spoken of being mistreated at similar bases across the country before being transferred to coalition prisons.

But the US military intelligence commander at Camp War Horse, Major Kreg Schnell, was adamant that his troops had not laid a finger on detainees.

Journalists taken on a guided tour of the facility saw no signs of physical abuse on Iraqi prisoners, kept in two large and sparse, but clean, pens.

They told the governor of Diyala, Abdullah al-Jaburri, who had demanded access to the centre, that they were not being humiliated.

The visit began with refreshments. The mood was cordial, but a member of the US-installed interim Governing Council complained.

"We must accelerate their (trials). We must have lists of names, know why the prisoners have been arrested and where they have been transferred," said Hafed Abdelaziz.

Request granted. Colonel Dana Pittard, commander of the 1st ID, based in the western area of the province, hands over the requested list.

"Have you been mistreated?" the governor asks the detainees, dressed in orange boilersuits.

"No. We have never been tortured," chorused those behind bars as some 50 soldiers stood nearby.

The infirmary, toilets, showers, interrogation room: everything is clean.

Schnell says his officers, and the military police, are fully versed in the Geneva Conventions and are properly trained.

"Here isn't Abu Ghraib", he said.

One interrogator explained his methods for getting prisoners to talk.

"I try to build a relationship and get their view point, and make them comfortable. Scaring them makes them shut down because they are afraid and they won't talk. I try to be friendly and open-minded," he said.