Iranian police have clashed with anti-government demonstrators who
gathered in the Iranian capital during a Shi'ite Muslim holiday.
Witnesses say police confronted protesters who had gathered Saturday in the streets around the Jamaran mosque in north Tehran, where reformist former president Mohammad Khatami was due to deliver a speech.
Earlier Saturday, reformist Web sites said riot police used tear gas to break up protests in central Tehran.
Witnesses say some of the demonstrators were beaten or arrested, and that riot police smashed the windows of passing cars.
One reformist news Web site (www.rahesabz.net) reports that in an effort to evade riot police, hundreds of protesters rode through Tehran in city buses, shouting slogans out the windows.
The reports come a day after a hardline Iranian cleric (Ahmad Khatami) warned anti-government activists not to use the solemn Ashura holiday to stage demonstrations.
Ashura ceremonies culminate Sunday.
During Ashura, Shi'ite worshipers mourn the seventh-century killing of Imam Hussein, the grandson of the Prophet Muhammad.
Reformists have recently been staging protests to coincide with public events.
Last week, hundreds of thousands of people attended the funeral of a dissident cleric Grand Ayatollah Hossein Ali Montazeri, an event that evolved into a giant anti-government demonstration.
Iranian authorities cracked down on the protesters at the funeral and at subsequent rallies following Montazeri's death.