U.S. and Iraqi forces killed some 300 gunmen from an apocalyptic Muslim cult in a day-long battle involving U.S. tanks and aircraft near the Shi'ite holy city of Najaf, Iraqi police, army and political sources said. The U.S. military said on Monday it was an ongoing operation so it could not provide any details. An Iraqi army source said U.S. forces took control of the operation on Sunday and had continued bombing the area until well after dawn on Monday. Two Americans were killed, the U.S. military said on Sunday, when an attack helicopter went down during the battle that...