Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Opposition Supporters, Police Clash in Iran VOA News 26 December 2009 Fierce clashes between government forces and opposition supporters in Iran are reportedly growing more violent and spreading. Reformist Web sites say the skirmishes broke out Saturday in central Tehran, and that riot police used tear gas to try to disperse the protesters. Witnesses say some of the demonstrators have been beaten or arrested, and that riot police smashed the windows of honking cars. One Web site, Rah-e-Sabz, says riot police have also been joined by elite government forces. Another Web site, Jaras, says some protesters sought shelter in a building belonging to the ISNA news agencies, but that government forces followed them inside. Reformists have recently been staging protests to coincide with public events. On Friday, a senior, hardline Iranian cleric Ahmad Khatami warned opposition activists not to use the holiday to stage anti-government protests. Saturday's demonstrations come as Iran's Shi'ite Muslims observe the Ashura religious holiday. Ashura ceremonies culminate Sunday. During the holiday, Shi'ite worshipers mourn the seventh-century killing of Imam Hussein, the grandson of the Prophet Muhammad. On Monday, 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 Monday's funeral and at subsequent rallies following Montazeri's death. Some information for this report was provided by AFP and AP. .