In a message delivered by a representative in a Friday sermon, Grand Ayatollah Ali al-Sistani also cautioned protesters who have staged weekly rallies to press demands for reform that they must guard against groups seeking to hijack their movement to further other interests.
Hours later, tens of thousands of Iraqis rallied in Baghdad and a string of cities south of the capital in support of Prime Minister Haider al-Abadi's reform drive and to press demands for the dissolution of parliament and an end to corruption.
Followers of a radical, anti-American Shiite cleric, Muqtada al-Sadr, joined the Baghdad rally for the first time on Friday. The smaller rallies were held in cities south of Baghdad, including the holy Shiite city of Karbala, the southern port of Basra and Babil.
Al-Sistani's comments, delivered in Karbala, challenged the government to show that it is "truthfully and seriously" responding to demands for change. "Citizens have experienced past promises that were never realized on the ground," he cautioned.