NAJAF, Iraq (CNN) -- A prominent aide to renegade Shiite Muslim cleric Muqtada al-Sadr was arrested early Wednesday in Najaf, according to U.S. military officials and a representative of al-Sadr's office.
His followers are widely blamed for the murder of a coalition-friendly cleric, Abdel Majid al-Khouei, in Najaf in April, soon after his return from exile.