According to the Washington Times:
A U.S. military intelligence report says that followers of radical Shi’ite cleric Sheik Muqtada al-Sadr imprisoned, killed and mutilated Iraqis who opposed his insurrection.
American intelligence officers are now investigating in the town of Najaf, the site of Sheik al-Sadr’s bloody standoff with coalition forces. A U.S. military officer told The Washington Times that the command recently acquired photos of 15 to 20 mutilated bodies that appear to be Iraqis lying in a courtyard.
An intelligence report from the Pentagon said some of the prisoners taken by al-Sadr’s forces “had eyes and ears drilled out and others had their limbs and heads cut off. Some males had genitals cut off and shoved in their mouths. There was evidence of rape to men, women and children”.
I want confirmation of this story before I take it at face value because it sounds a bit like propaganda (one Iraqi witness supposedly put the body count at 200). If true, however, it might explain how al-Sadr convinced his men to keep fighting even though they were surrounded by U.S. Marines.