"We urge all those who receive these calls to protest not to participate in these illegal gatherings as they will create problems for themselves and other citizens," said Interior Minister Abdolrahman Rahmani Fazli.
State news channel IRINN said it had been banned from covering the protests that spread from second city Mashhad on Thursday to hit several towns and cities.
The protests initially targeted economic problems, but quickly turned against the Islamic regime as a whole.
US President Donald Trump warned "the world is watching" after dozens of demonstrators were arrested.
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Media coverage inside Iran focused almost exclusively on pro-regime rallies held on Saturday to mark the defeat of the last major protest movement in 2009, which hardliners call "the sedition".
The timing was coincidental, since the rallies are held every year on this day, but offered a handy show of strength to the regime as huge crowds of black-clad supporters gathered across the country.
"The enemy wants once again to create a new plot and use social media and economic issues to foment a new sedition," Ayatollah Mohsen Araki told a crowd in Tehran, according to the conservative Fars news agency.
There were even chants in favour of the monarchy toppled by the Islamic revolution of 1979, while others criticised the regime for supporting the Palestinians and other regional movements rather than focusing on problems at home.
Footage showed thousands gathered in the cities of Rasht, Hamedan, Kermanshah, Qazvin and elsewhere, with police responding with water cannons.
Officials were quick to blame outside forces for the unrest.
"Although people have a right to protest, protesters must know how they are being directed," Massoumeh Ebtekar, vice president in charge of women's affairs, wrote on Twitter.
Nonetheless, officials warned against dismissing the public anger seen in recent days.