Police have clashed with opposition supporters during a rally in the Iranian capital, Tehran, reports say.
Police fired tear gas as demonstrators chanted "death to dictators", the reports cited witnesses as saying.
Police were also reported to have made several arrests, and to have used batons to disperse protesters.
Reformist leaders had urged supporters to turn out to peaceful rallies to mark 30 years since the seizure of the US embassy in Iran.
Iran's Revolutionary Guards had warned opposition groups not to hold protest rallies.
Since June, Iranian opposition supporters have been staging protests over elections they say were rigged to ensure the re-election of President Mahmoud Ahmadinejad.
Posts
