** FILE ** Mahdi Army Militia men gesture in the Shiite holy city of Najaf , 160 kilometers (100 miles) south of Baghdad, Iraq, in this Friday, May 28, 2004 file photo. Rivalries and violence between Shiite factions are threatening to overshadow progress U.S. forces have made against al-Qaida in Iraq and other extremists just weeks before the top American commander and diplomat in Iraq report to Congress. (AP Photo)