Banners in the colours of the Iranian flag adorn a roundabout as cars drive past in the Iranian capital Tehran. AFP
Iran's Tasnim news agency quoted the police chief in the city of Yazd as saying those arrested were involved "in organising, inciting and directing riotous actions, and in some cases were in contact with networks outside the country".
The nationalities of those held were not specified.
"During the review of cases related to the recent rioters, it was determined that 139 of those arrested in these disturbances were foreign nationals," police chief Ahmad Negahban said.
Protests against the rising cost of living broke out in Iran on December 28 before morphing into nationwide anti-government demonstrations.
Tehran has acknowledged that more than 3,000 deaths occurred during the unrest, but insists that most were members of the security forces and innocent bystanders, attributing the violence to "terrorist acts".
The Human Rights Activists News Agency, an opposition Iranian US-based NGO, says it has confirmed 6,854 deaths, mostly protesters killed by security forces.
Iranian authorities have said the rallies began as peaceful demonstrations before turning into "riots" involving killings and vandalism that were inflamed by arch-foes the United States and Israel.
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