President Ebrahim Raisi struck a defiant tone on a visit to the United Nations, with demonstrators also trailing him on the streets of New York and dissidents filing a human rights lawsuit against the hardline cleric.
Public anger has flared in the Islamic republic since authorities on Friday announced the death of 22-year-old Mahsa Amini, who had been held for allegedly wearing a hijab headscarf in an "improper" way.
Activists said the woman, whose Kurdish first name is Jhina, had suffered a fatal blow to the head, a claim denied by officials, who have announced an investigation.
Some women demonstrators have defiantly taken off their hijabs and burned them in bonfires or symbolically cut their hair before cheering crowds, video footage spread on social media has shown.
"No to the headscarf, no to the turban, yes to freedom and equality!" protesters in Tehran were heard chanting in a rally that has been echoed by solidarity protests abroad.
Iranian state media reported Wednesday that, in a fifth night of street rallies that had spread to 15 cities, police used tear gas and made arrests to disperse crowds of up to 1,000 people.
London-based rights group Article 19 said it was "deeply concerned by reports of the unlawful use of force by Iranian police and security forces," including the use of live ammunition.
Demonstrators hurled stones at security forces, set fire to police vehicles and garbage bins and chanted anti-government slogans, the official IRNA news agency said, adding that rallies were held in cities including Mashhad, Tabriz, Isfahan and Shiraz.
"Death to the dictator" and "Woman, life, freedom," protesters could be heard shouting in video footage that spread beyond Iran, despite online restrictions reported by internet access monitor Netblocks.
At the United Nations, British Foreign Secretary James Cleverly told AFP that "the Iranian leadership should notice that the people are unhappy with the direction that they have taken."
"They could abandon their nuclear weapons aspirations. They could stop the repression of voices within their own country. They could stop their destabilizing activities," he said.
"A different path is possible. That is the path that we want Iran to take and that is the path that will see them with a stronger economy, a more happy society and a more active part in the international community."
Raisi, addressing the UN General Assembly, pointed to the deaths of Indigenous women in Canada as well as Israeli actions in the Palestinian territories and the Islamic State group's "savagery" against women from religious minority groups.
"So long as we have this double standard, where attention is solely focused on one side and not all equally, we will not have true justice and fairness," Raisi said.
He also pushed back on Western terms to revive a 2015 nuclear accord, insisting that Iran "is not seeking to build or obtain nuclear weapons and such weapons have no place in our doctrine."
But attention has quickly shifted to the protests, which are among the most serious in Iran since November 2019 unrest over fuel price rises.
French President Emmanuel Macron said he asked Raisi in a meeting Tuesday to show "respect for women's rights."
The wave of protests over Amini's death "is a very significant shock, it is a societal crisis," said Iran expert David Rigoulet-Roze of the French Institute for International and Strategic Affairs.
"It is difficult to know the outcome but there is a disconnect between the authorities with their DNA of the Islamic revolution of 1979 and an increasingly secularized society," he said.
"It is a whole social project that is being called into question. There is a hesitation among the authorities on the way forward with regard to this movement."
Protests first erupted Friday in Amini's home province of Kurdistan, where governor Ismail Zarei Koosha said Tuesday three people had been killed in "a plot by the enemy."
Kurdistan police commander Ali Azadi on Wednesday announced the death of another person, according to Tasnim news agency.
Two more protesters "were killed during the riots" in Kermanshah province, the region's prosecutor Shahram Karami was quoted as saying by Fars news agency, blaming "counter-revolutionary agents."
Additionally, Norway-based Kurdish rights group Hengaw said two protesters, aged 16 and 23, had been killed overnight in West Azerbaijan province.
An additional 450 people had been wounded and 500 arrested, the group said, figures that could not be independently verified.
Video spread online showing security forces opening fire on protesters in the southern city of Shiraz.