Supporters of an anti-U.S. cleric clashed with security forces to protest an Iraqi army raid on his office Tuesday, forcing authorities to impose a curfew in this holy city, officials said. No casualties were reported. Iraqi soldiers raided the office of cleric Mahmoud al-Hassani before dawn, apparently because his supporters had taken over a field behind the building for security reasons, said Ahmed al-Ghazali, an aide to the cleric. He claimed the soldiers opened fire but the cleric's supporters did not respond. Army officials could not be immediately reached to confirm the claim. Al-Ghazali said that later in the day, armed supporters of al-Hassani attacked police stations and police checkpoints in Karbala, triggering minor gunbattles. An indefinite curfew was imposed in Karbala, 80 kilometers (50 miles) south of Baghdad, after the clashes, said Ghalib al-Daami, a member of the Karbala provincial council. «We have asked for extra forces from neighboring provinces to control the situation after clashes erupted between al-Hassani's supporters and the security forces,» he told The Associated Press. « We will arrest any one found carrying weapon in the streets,» he said.