Iran's clerical rulers have stepped up suppression of persistent anti-government protests in the country's Kurdish region, deploying troops and killing at least four demonstrators on Sunday, social media posts and rights groups said.
Nationwide protests, sparked by the death of 22-year-old Iranian Kurdish woman Mahsa Amini in September in the custody of morality police, have been at their most intense in the areas where the majority of Iran's 10 million Kurds live.
Videos on social media, unverifiable by Reuters, showed a convoy of military vehicles with heavily armed troops, purportedly in the western city of Mahabad. The sounds of heavy weaponry could be heard in several other videos.
The Norway-based human rights group Hengaw said military helicopters carried members of the widely feared Revolutionary Guards to quell the protests in the Sunni-dominated Kurdish city of Mahabad.
In a statement, carried by state media, the Guards confirmed "strengthening" their forces in the northwestern Kurdish region to confront "terrorist separatist groups" in the area.
"The security of the people is our red line ... and dealing decisively with terrorists is our mandate,"the statement said.
Iranian authorities, who have blamed Amini's death on pre-existing medical conditions, say the unrest has been fomented by foreign adversaries and accuse armed separatists of perpetrating violence.
Prominent Sunni cleric Molavi Abdolhamid, a powerful dissenting voice in the Shi'ite-ruled Islamic Republic, called on security forces to refrain from shooting at people in Mahabad.
"Disturbing news is emerging from the Kurdish areas, especially from Mahabad ... pressure and crackdown will lead to further dissatisfaction," Abdolhamid tweeted.
Hengaw said at least four protesters were killed in the Kurdish area. The widely-followed activist account 1500Tasvir said a 16-year-old student and a school teacher were killed in the Kurdish city of Javanrud. The details could not be independently confirmed.
Iran's state media said calm had been restored in the area. But activists and Hengaw said on Twitter that "the resistance" continued in several Kurdish cities.
"In (the Kurdish city of) Marivan repressive forces have opened fire at people," Hengaw said.
The uprising has turned into a popular revolt by furious Iranians from all layers of society, posing one of the boldest challenges to the clerical leaders since the 1979 Islamic revolution that swept them to power.
Ehsan Hajsafi, a footballer who normally plays in Athens, became on Sunday the first member of Iran's national team to speak out from the World Cup in Doha in apparent support of the protests at home. Other players have kept silent, and some activists have called for protests against the team.
Protests have stretched into a third month despite violent state clampdown and death sentences issued for at least six protesters.
HRANA said 410 protesters had been killed in the unrest as of Saturday, including 58 minors. Some 54 members of the security forces were also killed, it said, adding that more than 17,251 people have been arrested. Authorities have not provided an estimate of any wider death count.
Two Iranian actresses, who had posted pictures of themselves on Instagram without the compulsory headscarf in solidarity with the protest, were arrested on Sunday for stoking protests, Iranian state media reported.
Videos posted on social media showed Iranians in several other cities kept up protests, from Tehran to the northwestern city of Tabriz, calling for the toppling of the Islamic Republic and chanting "Death to (Supreme Leader Ayatollah Ali) Khamenei".