The sentencing came as Britain announced it would redeploy some 850 troops from their relatively safe base in south Iraq to a more hostile area near Baghdad to relieve US troops.

Defence Secretary Geoff Hoon said the redeployment requested by the United States would last "weeks rather than months." The move has provoked widespread anger in Britain.

In Baghdad, Judge Colonel James Pohl also sentenced Frederick, the highest ranking soldier to be charged in the Abu Ghraib scandal, to a reduction in rank to private, a forfeiture of pay and a dishonorable discharge from the army.

Frederick's lawyer Gary Myers called the sentence excessive and said he would appeal. The other two soldiers so far convicted were jailed for eight months and one year.

Frederick, 38, had pleaded guilty to five charges of abusing detainees at Abu Ghraib in October and November last year, including making three prisoners masturbate. He also punched one prisoner so hard in the chest that he needed resuscitation.

Major Michael Holley, the military prosecutor, told the court: "He's (Frederick) an adult and capable of telling, as we learned, the difference between right and wrong.

"How much training do you need to learn that it's wrong to force a man to masturbate?"

The Abu Ghraib affair shocked the world when it broke in April with pictures splashed across the media. Five more military police, including three women, are due to face courts martial in the coming months, two more of them this week.

In Britain, Hoon said the troop movement was to help boost security for Iraqi elections due in January.

"This deployment is a vital part of the process of creating the right conditions for the Iraqi elections to take place," he told parliament.

Some critics have accused British Prime Minister Tony Blair of trying to help President Bush's re-election bid.

A senior Bush administration official called that idea preposterous. "It is clearly a request made by military commanders based on military needs," said the official, who asked not to be identified.

Hoon gave no precise details about when the forces would move or to where, but he said they would remain under the operational command of British military chiefs, not Americans.