Four British soldiers face charges of assaulting Iraqi prisoners, including a charge that they photographed detainees whom they had forced to engage in sex acts with each other, Britain's attorney general announced on Monday.

In a statement to the House of Lords, Attorney General Peter Goldsmith said the case was the first of eight involving British troops that had been turned over to army prosecutors for possible trial. A ninth case, involving the killing of an Iraqi civilian who was beaten to death while in custody, was being examined by civilian prosecutors, Goldsmith said.

The armed forces minister told Parliament last week that the military was investigating 75 cases involving the deaths, injuries or alleged mistreatment of Iraqi civilians. Many of the allegations echo those made against U.S. military personnel charged with assaulting and mistreating Iraqis at the Abu Ghraib prison outside Baghdad, although British officials have insisted that the cases so far do not suggest the degree of systematic and widespread abuse allegedly practiced at Abu Ghraib. Officials have promised to investigate all allegations thoroughly.

The four soldiers, all members of the Royal Regiment of Fusiliers, are charged with assault, indecent assault and "prejudicing good order and military discipline." The alleged victims were Iraqi civilians who were being temporarily detained but were not held in a prison or detention facility, according to the attorney general's statement.

The allegations came to light when a shop attendant at a photography store in central England noticed the content of a roll of film that a soldier had brought to be developed. The attendant, Kelly Tilford, told reporters that four of the photos were obscene.

"The men who were performing the sex acts looked totally disgusted," Tilford told the Sunday Times of London. "You could tell they were being forced into it. The Iraqis looked absolutely terrified."

Tilford turned over the film to local police in May 2003, and they arrested the soldier when he returned to pick up the prints. There was no immediate indication why it took 13 months for the arrest to lead to a military prosecution.

About 8,000 British troops are stationed in southern Iraq. For the most part they have not endured the same level of attacks as their American counterparts in central Iraq, and British officials have expressed pride in the friendly relations their troops have maintained with local Iraqis.

But Amnesty International charged in a report in May that British soldiers had opened fire and killed Iraqi civilians "in circumstances where there was apparently no imminent threat of death or serious injury to themselves or others." A British court has agreed to hear cases brought by a dozen Iraqi families alleging wrongful killings by soldiers.

Britain has acknowledged its troops have killed 27 Iraqi civilians, including an 8-year-old girl allegedly shot inadvertently during a stone-throwing incident and a 26-year-old hotel receptionist beaten to death while in custody.