keywords: militias insurgency besieged tanks najaf
text: U.S. Planes Hit Militias as Tanks Near Najaf Shrine  NAJAF, Iraq (Reuters) - U.S. helicopter gunships pounded  Shi'ite militias in the holy Iraqi city of Najaf on Sunday as  tanks rumbled to within 800 meters (yards) of a besieged shrine  at the center of a near three-week insurgency.