PRESIDENT Barack Obama will try to block the court-ordered release of photos showing US troops abusing prisoners, in an abrupt U-turn on his previous position.

He said the change of mind came out of concern that the pictures would "further inflame anti-American opinion" and endanger US forces in Iraq and Afghanistan.

The White House had said last month it would not oppose an appeals court ruling that set a May 28 deadline for releasing dozens of photos from military investigations of alleged misconduct.

But American commanders in the war zones have expressed deep concern about fresh damage the photos might do, especially as the US tries to wind down the Iraq war and step up operations against the Taliban and al Qaida in Afghan- istan.

When photos emerged in 2004 from the infamous US-run Abu Ghraib prison in Iraq, showing grinning soldiers posing with detainees, the pictures caused a huge anti-American backlash around the globe, particularly among Muslims.

Mr Obama, explaining his change of heart on releasing the other photos, said they already had served their purpose in investigations of "a small number of individuals".

Those cases were all concluded by 2004, and the president said "the individuals who were involved have been identified, and appropriate actions have been taken".