Al-Sadr's remarks were read in a mosque in Kufa, a Shi'ite holy city south of Baghdad.
They came after at least 181 people were killed or found dead on March 29 as Sunni insurgents apparently stepped up their campaign of bombings.
Al-Sadr supporters demonstrating against the U.S. presence in Iraq in October 2006 (epa)
A RADICAL CLERIC. Shi'ite cleric Muqtada al-Sadr is a key figure in Iraq. He heads the Imam Al-Mahdi Army militia and a political bloc that is prominent in parliament and the government. His ties to Iran have also provoked concerns in some quarters.