Shiites Hold Najaf Shrine; Clashes Flare NAJAF, Iraq - Militants loyal to radical Shiite cleric Muqtada al-Sadr kept their hold on a revered shrine, and clashes flared in Najaf on Saturday, raising fears that a resolution to the crisis in the holy city could collapse amid bickering between Shiite leaders.    An unofficial mediator pleaded with al-Sadr to disarm his militants, pull them out of the shrine and disband his militia immediately...