Fresh protests broke out in Tehran as night fell on Monday, with images of burning cars on local media and online reports of heavy police presence.
The conservative-linked Fars news agency showed a burning car, while social media reports said relatively small groups were chanting anti-regime slogans in downtown parts of the capital.
"A troublemaker set fire to a taxi and immediately fled," said the Mehr news agency in one of the few reports by local media.
It marks the fifth day of unrest in Iran that began with anger over the state of the economy and soon turned against the Islamic regime as a whole.
The intelligence ministry released a statement saying that "rioters and instigators of recent unrest have been identified and some have been arrested".
