Meanwhile, U.S. and Iraqi officials are claiming more than 600 members of the militia run by Shiite leader Muqtada al-Sadr have been detained. The Pentagon recently announced that Sadr’s milita — the Mahdi Army — had replaced al-Qaeda in Iraq as the most dangerous factor fueling the sectarian violence in the country. Up until this week, Iraqi Prime Minister Nouri al-Maliki relied on Sadr’s Mahdi Army as his security force.