Iranian police say they have arrested 50 people during clashes between opposition supporters and police in Tehran during a new year festival.
The Feast of Fire comes on the eve of the Persian new year, but religious leaders had told Iranians celebrating it was “un-Islamic”.
There were a number of clashes between young people and the police across the capital, a Tehran police chief said.
Opposition leaders had told people not to protest during the festival.
The BBC’s correspondent Jon Leyne says there is no sign these clashes will widen into a bigger political protest.
The clashes were more a show of defiance against demands from religious authorities that Iranians refuse to celebrate the festival, our correspondent says.
Young Iranians went out into the street to leap though bonfires and set off firecrackers, traditional on Chaharshanbeh-Suri – or Red Wednesday – held a few days before Norouz, the Persian new year.
Large protests have been held during public events since June’s disputed election.