Iranian police have asked people to send photos and videos of "trouble-makers," local media reported, and to identify suspects already caught on camera.
Pro-government rallies
State media have released photos of pro-government rallies in several cities, including Tabriz, in northwestern Iran. It marked the third day of such demonstrations.
More from hard-line cleric Ahmad Khatami, who is speaking during Friday prayers in Tehran, via AP.
Khatami called on Iran to create its own indigenous social media websites, blaming Western apps for the unrest that followed days of protests.
Khatami said that "the nation does not support a social network that its key is in the hand of the United States." He also said he believed anyone who burned Iran's flag should be sentenced to death.
More from hard-line cleric Ahmad Khatami, who is speaking during Friday prayers in Tehran.
Students Arrested
RFE/RL's Radio Farda reports that at least 37 Iranian students have been arrested in recent days amid nationwide antigovernment protests.
Friday Prayers
Hard-line cleric Ahmad Khatami is speaking after Friday prayers at the Imam Khomeini Mosalla Mosque in Tehran.
He backs the government's blocking of social media in a bid to disrupt the spread of information about the protests.
Latest from RFE/RL's news desk
Pro-government demonstrators plan to take to the streets of Iran again on January 5 ahead of a United Nations Security Council emergency meeting about deadly antigovernment protests in the country during the past week.
Reports in Western media about antigovernment demonstrations in Iran have decreased since Tehran blocked key social media sites used by the protesters to spread video of the earlier unrest.
But RFE/RL has obtained credible reports on January 5 from sources in Iran about ongoing demonstrations against Iran's clerical rulers in Tehran and other cities -- the strongest challenge to the country’s Islamic leadership in almost a decade.
Iranian state media has not been covering the antigovernment demonstrations since Iran's Islamic Revolutionary Guards Corps (IRGC) claimed on January 3 that the demonstrations were over.
But state media has reported that the IRGC is continuing to deploy security forces in different parts of the country.
At least 22 people have been killed in clashes between the antigovernment demonstrators and security forces and more than 1,000 protesters reportedly have been arrested.
State media also has been reporting on pro-government rallies organized by authorities in recent days.
Iranian state media says about 40 pro-government rallies were expected in Tehran Province after Friday prayers on January 5.
The UN Security Council was due to meet later on January 5 at the behest of the United States and over strong objections raised by Russia.
Antigovernment Protest In Mashhad
Footage has emerged of a protest late January 4 in the city of Mashhad, where the protests first began on December 28.