U.S. and Iraqi forces say they have killed as many as 300 gunmen in Najaf in what has been described as one of Iraq’s deadliest battles in years. The U.S. sent in tanks and aircraft during the 15-hour fight. Two U.S. soldiers died after their helicopter was shot down. Some officials have described the target of the attack as members of an apocalyptic Muslim cult who were planning to disrupt the Shiite holy festival of Ashura.