The Pentagon is releasing nearly 200 photographs of detainees in Iraq and Afghanistan, taken mostly between 2004 and 2006, involving 56 cases of alleged abuse by U.S. forces.

The often dark, blurry and grainy pictures are mainly of detainees' arms and legs, revealing bruises and cuts.

The abuse appears much less severe than that seen in photos of alleged torture victims at Iraq's Abu Ghraib prison in the early years of that war, including images of naked detainees stacked in a human pyramid or of a soldier holding a naked detainee by a dog collar and leash.

Investigations substantiated abuse in 14 of the cases linked to the 198 newly released photos, and determined that 42 allegations were not valid. Sixty-five service members were disciplined in connection with the cases.