Sydney & Washington: An Australian television station broadcast on Wednesday what it said were previously unpublished images of abuse of Iraqi prisoners at Abu Ghraib prison, fuelling more Arab anger against the United States.

The Pentagon confirmed the authenticity of the images and highlighted its concern at their potential impact.

"The department believes that the further release of images could only further inflame and possibly incite unnecessary violence in the world and would endanger our military men and women that are serving in places around the world," said Bryan Whitman, a Pentagon spokesman.

In Sydney, Australian Prime Minister John Howard on Thursday defended the United States, saying it has dealt with abuse at Iraq's Abu Ghraib prison.

"If further abuse has occurred then I unreservedly condemn it," said Howard.

"But can I say immediately in defense of the Americans, they are doing something about it," he said.

The Special Broadcasting Service's "Dateline" current affairs programme said the images were recorded at the same time as the now-infamous pictures of US soldiers abusing Abu Ghraib detainees which sparked international outrage in 2004.

Dateline executive producer Mike Carey said the programme had obtained a file containing hundreds of pictures - some that have been seen before and others that show new abuses.

Carey declined to say where or how the station had got hold of the images.

Some of the images were shown last year at trials in Fort Hood, Texas, including against abuse ringleader Charles Graner who is now serving a 10-year prison sentence.

The official investigations blamed the abuse on a breakdown of unit discipline at Abu Ghraib rather than official policy.

Pentagon spokesman Whitman said the abuses at Abu Ghraib had already been fully investigated."In Abu Ghraib specifically, there have been more than 25 individuals - officer and enlisted - that have been held accountable for criminal acts and other failures."

The American Civil Liberties Union in New York said the United States must aggressively investigate the abuses.

"The overwhelming majority of the photos I've seen are photos that have been in existence for years that were on Charles Graner's hard drive," said one official, who did not want to be named because of concerns of possible prosecution for discussing the images.

Graner appears in several of the images, and others showed different photos of an Iraqi who was later humiliated in now notorious images showing him with a lease to his neck.

The grainy, still photographs and video images show prisoners, some bleeding or hooded, bound to beds and doors, sometimes with a smiling American guard beside them.

They include two naked men handcuffed together, a pile of five naked detainees photographed from the rear, and a dog straining at a leash close to the face of a crouching man wearing a bright orange jumpsuit.

A soldier from Graner's unit said he had seen the newly published images before, and said the corpses were among three Iraqis killed in a riot in an open-air part of Abu Ghraib.

"That was from a riot that happened," the soldier said of one image. "They're old pictures, nothing new and sizzling."

The images were swiftly re-broadcast by Arab satellite television stations and several news organisations, including American ABC News television, showed them on their Web sites.

They stirred up more anger among Arabs, already incensed by the publication on Sunday of images of British soldiers apparently beating Iraqi youths and by cartoons satirising the Prophet Mohammad (PBUH) printed in European papers this month.

"This is truly American ugliness that no other country in the world can compete with," journalist Saleh Al Humaidi told reporters in Yemen.

"The Americans ought to apologise to mankind for their government's lie to the world that it is fighting for freedom and that it came to Iraq to save it from Saddam Hussain's oppression.

In Iraq, anger grew as more television stations broadcast the images.

"It makes you feel humiliated as an Iraqi," said Mehdi Jumbas, a technician in Baghdad. "The government should act, not let this pass. They should do something about these jails... Last time what happened? Nothing."