According to Press TV, for the second consecutive day, demonstrators flooded the cities in several town and cities, including the northeastern holy city of Mashhad, Isfahan, Shiraz, Rasht, Yasoij, Ardabil and Urmia.
Demonstrators were holding up national flags and portraits of Leader of the Islamic Revolution Ayatollah Seyyed Ali Khamenei, shouting pro-establishment slogans.
The participants also held the US and the Israeli regime responsible for the recent wave of violence in Iran.
Similar rallies were held in a number of Iranian cities on Wednesday, while people in the capital, Tehran, are set to hold a demonstration after noon prayers on Friday.
Last week, a number of peaceful protests over economic grievances started in several cities, but those gatherings suspiciously changed color and turned ugly when groups of participants, some of them armed, launched attacks on public property, police stations and religious sites.
The original protesters soon left the streets upon calls by the authorities so security forces could deal with the rioters and sporadic violence, which continued in some towns and cities for several days.
Over a dozen people have been killed in the violence, according to state media reports.
The violence drew praise from Tel Aviv and Washington, which voiced firm support for the rioters.
President Hassan Rouhani has said that based on the rights enshrined in the Constitution and the Charter of Civil Rights, people are free to criticize the government or stage protests, but the manner of expressing such criticism should be constructive and help improve domestic conditions.