Supreme Council for the Islamic Revolution in Iraq (SCIRI) Based in Iran, it has been the main Shiite anti-Saddam Hussein group for years, with 10,000 armed fighters in its Badr Brigades. It is extremely close to the Iranian regime and fought for it in the Iran-Iraq war of the 1980s. For months recently U.S. officials tried to bring SCIRI into its coalition of Iraqi opposition groups, but then rejected the idea because of SCIRI's intimate ties to Tehran. Those ties also engender skepticism among many Iraqis, including some Shiites. It is led by Mohammed Bakir Hakim. Dawa Islamiya (Islamic Call) Another Anti-Hussein group, divided into competing factions, some in Iran and others dispersed elsewhere. One team of Dawa agents wounded Uday Hussein in a 1996 assassination attempt. Some of its leaders are suspicious of Iran, and others work closely with Tehran. A number are secular, while others are clerics. Followers of Muqtada Sadr At 22, he is trying to gain control of the holy Shiite city of Najef, and is threatening other leaders who have any influence there. He gains legitimacy from his father, Grand Ayatollah Mohammed Sadiq Sadr, who is highly revered for stirring Shiite opposition to Hussein before his 1999 execution by the Baathists. In recent days, the son, who is bitterly anti-American, has ordered other leading clerics to leave Najaf. Many Shiites say he was behind last week's killing of a U.S.-allied cleric, Majid Khoei, at a Najaf holy site. Sources differ on whether he is pro- or anti-Iran. Ayatollah Ali Sistani He is the leading Shiite cleric in Iraq, and is based in the holy city of Najaf. He was jailed off and on by Hussein, but in general did not actively organize resistance against him. Partly for that reason he is opposed by the more radical Sadr faction, which a few days ago surrounded his house and ordered him to leave Najaf. Ad U.S. forces entered Iraq, he released a statement saying Muslims should not oppose them. Khoei Foundation The London-based foundation that funds Shiite causes around the world is financed by followers of a deceased ayatollah of that name. For months U.S. forces worked closely with his son, Abdul Majid Khoei, and hoped he would help win Iraqi Shiites over to the U.S. cause. U.S. officials helped him travel from Britain to Iraq in the war's early days. But some Shiites resented that he had not given control of his father's foundation to Sistani, and he lacked a large following in Iraq. Last week, Khoei was stabbed to death by a mob at a Najaf shrine as he met a formerly pro-Hussein cleric. --John Mintz