Iran's Intelligence Ministry has warned that attending protests over the death of a woman in police custody is illegal and anyone who takes part will face prosecution, Iranian news websites have reported.
Protests that began on Saturday following the death in custody of Mahsa Amini, who had been arrested for wearing "unsuitable attire", have now spread to over 80 Iranian cities.
Women have played a prominent role in the demonstrations, waving and burning their veils, with some cutting their hair in public in a direct challenge to clerical leaders.
A human rights group said at least 31 civilians had been killed in the unrest, while state television put the death toll at 17.
In Tehran and some Kurdish cities, protesters torched police stations and vehicles on Thursday as public outrage over the death showed no signs of easing, with reports of security forces coming under attack.
"Considering the exploitation of recent incidents (protests) by counter-revolutionary (opposition) movements, any presence and participation in such illegal gatherings ... will result in judicial prosecution," the websites quoted the ministry as saying in a statement.
Ms Amini, 22, fell into a coma while in detention, and later died in hospital.
Iranian President Ebrahim Raisi has announced an investigation into the cause of her death. Authorities have denied harming her.
Footage on social media from the northern city of Tabriz showed a young man allegedly shot by security forces bleeding out in the street as protesters shouted for help.
Another video showed a policeman firing a shotgun at a demonstrator who was tearing down a pro-government billboard in North Khorasan province. It was unclear if he was wounded.
In another video, protesters could be seen torching a massive billboard showing Qassem Soleimani — Iran’s top general who was killed in a US air strike — in his hometown of Kerman.
The footage could not be independently verified.
Raisi accuses US of 'double standards'
Speaking during a news conference on the sidelines of the United Nations General Assembly, Mr Raisi issued a warning to protesters, saying: "There is freedom of expression in Iran ... but acts of chaos are unacceptable."
While Mr Raisi said Ms Amini's death must be "steadfastly" investigated, the Iranian president accused the US of "double standards", asking: "What about the death of Americans at the hands of US law enforcement?"
"Did all these deaths get investigated?"
He also mentioned deaths of women in Britain that he said were not investigated. He called for the "same standard" around the world in dealing with such deaths at the hands of authorities.
Earlier, Iran's powerful Revolutionary Guards group called on the Islamic Republic's judiciary to prosecute anyone spreading "false news and rumours" about Ms Amini's death.
In the statement, the Guards also expressed sympathy with the Ms Amini's family.
'Do not spare the criminals'
Pro-government protests were planned for Friday, Iranian media said.
"The will of the Iranian people is this: do not spare the criminals," said an editorial in the influential hardline Kayhan newspaper.
The protests over Ms Amini's death are the biggest in the Islamic Republic since 2019. Most of the demonstrations have been concentrated in Iran's Kurdish-populated north-west.
A group of United Nations experts, including Javaid Rehman, special rapporteur on human rights in Iran, and Mary Lawlor, special rapporteur on the situation of human rights defenders, demanded accountability for Ms Amini's death.
"We are shocked and deeply saddened by the death of Ms Amini," they said in a statement.
"She is another victim of Iran's sustained repression and systematic discrimination against women and the imposition of discriminatory dress codes that deprive women of bodily autonomy and the freedoms of opinion, expression and belief."
The United States on Thursday imposed sanctions on Iran's morality police, accusing them of abuse and violence against Iranian women and of violating the rights of peaceful Iranian protesters, the US Treasury said.
'Rioters and gangs' kill security forces
A member of an Iranian pro-government paramilitary organisation, the Basij, was stabbed to death in the north-eastern city of Mashhad on Wednesday, two semi-official Iranian news agencies reported on Thursday.
The Tasnim and Fars news agencies' reports of the stabbing appeared on Telegram as both their websites were not functioning on Thursday. There was no official confirmation of the death.
Tasnim also said another member of the Basij was killed on Wednesday in the city of Qazvin as a result of a gunshot wound inflicted by "rioters and gangs".
Nour News, a media outlet affiliated with a top security body, shared a video of an army officer confirming the death of a soldier in the unrest, bringing the total reported number of security force members killed in the unrest to five.
Social media footage, apparently filmed at protests in the north-east, showed demonstrators shouting: "We will die, we will die but we'll get Iran back" near a police station, which was set on fire.
The footage, which could not be verified, was posted on the Twitter account @1500tasvir, which focuses on Iranian protests and has more than 100,000 followers.
Another police station was set ablaze in the capital Tehran as the unrest spread from Kurdistan, the home province of Ms Amini and where she was buried on Saturday.
With no sign of the protests easing, authorities restricted access to the internet on Thursday, according to internet shutdown observatory NetBlocks.
Personal freedoms
Ms Amini's death has reignited anger over issues including restrictions on personal freedoms in Iran — including strict dress codes for women — and an economy reeling from sanctions.
Iran's clerical rulers fear a revival of the 2019 protests that erupted over gasoline price rises, the bloodiest in the Islamic Republic's history.
Some 1,500 people were killed in those protests.
Protesters also expressed anger at Supreme Leader Ayatollah Ali Khamenei.
"Mojtaba, may you die and not become Supreme Leader," a crowd was seen chanting in Tehran, referring to Khamenei's son, who some believe could succeed his father at the top of Iran's political establishment.
ABC/wires
