Iraq's top Shi'ite cleric, Grand Ayatollah Ali Husseini al-Sistani, has arrived at the holy city of Najaf to start talks aimed at ending weeks of fighting between US forces and Iraqi insurgents. A 24-hour truce ordered by Iraqi Prime Minister Iyad Allawi is now in force. According to Allawi Moqtada al Sadr, whose fighters are holed up in the revered Imam Ali mosque in Najaf, would abide by Ayatollah Sistani's plan to end the three-week uprising. Iyad Allawi has offered Sadr safe passage if he agrees to the plan. The 73-year-old Ayatollah and his aides drove to Najaf in a convoy of more than 1,000 cars, pick-up trucks, taxis and buses packed with Shiite faithful of all ages.