A British newspaper released a video today apparently showing British soldiers savagely beating Iraqi teenagers in 2004, prompting Prime Minister Tony Blair to promise a full investigation.
"We take seriously any allegations of mistreatment, and this will be investigated very fully indeed," Mr Blair told reporters after a meeting of left-of-centre leaders in South Africa.
"But I have to say to you that the overwhelming majority of British troops in Iraq, as elsewhere, behave properly and are doing a great job. They are helping Iraqis to become the democracy they would like to be."
The video, released by the News of the World and shown widely on British television as well as Arabic news stations, showed a group of soldiers dragging Iraqi protestors behind a wall while a demonstration is under way, and beating them with batons and kicking them.
The News of the World newspaper, which released the footage, said it had been filmed from the roof of a building by another soldier who can be heard egging on his comrades and mocking the Iraqis' pleas for mercy.
The Ministry of Defence said military police were investigating.
"We are aware of these very serious allegations and can confirm they are now the subject of an urgent Royal Military Police investigation," the Defence Ministry said in a statement.
"We condemn all acts of abuse and brutality and always treat any allegations of wrongdoing extremely seriously."
The newspaper said the video had been filmed in early 2004 at a time of street riots in southern Iraq, where British troops are stationed.
The cameraman is said to be heard laughing and saying: "Oh yes! Oh Yes! You're gonna get it. Yes, naughty little boys. You little fuckers, you little fuckers. Die. Ha Ha."
British troops have been hit by abuse allegations in the past, though none approaching the scale of the abuse perpetrated by Americans against prisoners at Abu Ghraib jail in Baghdad in a scandal that shocked the world in 2004.
Three British soldiers were jailed last year in a case launched over pictures taken in 2003 that showed Iraqi prisoners being beaten, stomped on and forced to pose in sexually humiliating positions.
Those pictures came to light when one of the soldiers took them to a lab to be developed and the lab technician alerted the authorities. But another set of photos of alleged abuse that appeared in the Mirror newspaper proved to be a hoax.