Meanwhile the U.S. military has charged four of its soldiers with punching, kicking and breaking the bones of Iraqi prisoners of war. The four officers, all from a Pennsylvania-based Army Reserve unit, are the first known U.S. troops to face such charges in Iraq. Last month human rights group Amnesty International issued a study that had found the U.S. was violating international law by subjecting Iraqi prisoners to “cruel, inhuman or degrading’’ conditions.