The U.S. military says that 600 Mehdi Army fighters have been captured, including 16 militia leaders. The Shia fighters, loyal to cleric Moqtada al-Sadr, have been captured in more than 50 operations over the past 45 days. The Medhi Army is reported to have as many as 600,000 fighters. Meanwhile on Capitol Hill, there is a split in the Republican Party on how to proceed in Iraq. Republican Representatives in both the House and the Senate expressed deep concerns about President Bush's plans for Iraq, particularly troop escalation. That concern was obvious today at the Senate Armed Services Committee hearing, as Lt. General David Patraeus testified to be the new Iraq commander. Nan McCurdy has more from Capitol Hill.