Iranian President Ebrahim Raisi said that the hijab was the law in Iran after a viral video showed a man throwing yoghurt at two unveiled women in a shop in a town near the northeastern city of Mashhad.
In live remarks on state television, Raisi said: "If some people say they don't believe (in the hijab)... it's good to use persuasion ... But the important point is that there is a legal requirement ... and the hijab is today a legal matter."
Video footage widely shared on social media in Iran appeared to show the two female customers, who were not wearing the mandatory hijab or headscarf, in a shop being assaulted by a man after a verbal altercation.
The footage shows the man pouring a bucket of what appears to be yogurt on the two women's heads before he is confronted by the shopkeeper.
Arrest warrants for attacker and women
Judicial authorities issued arrest warrants for the man seen pouring yoghurt over the heads of the two women, a mother and her daughter. They were also the subject of arrest warrants for flouting Iran's strict female dress rules, state media reported.
Authorities said the owner of the dairy shop, who confronted the attacker, had been warned. Reports on social media showed his shop had been shut, although he was quoted by a local news agency as saying he had been allowed to reopen and was due to "give explanations" to a court.
The incident comes after the death in custody of Iranian Kurd Mahsa Amini in September sparked months of nationwide protests. The 22-year-old had been arrested for violating Islamic dress codes. More than 500 demonstrators were killed during the protests that followed.
Chief Justice threatens punishment
Meanwhile, Iran's Chief Justice has threatened that individuals who do not follow strict rules about modest dress in the public will be punished.
Gholam-Hossein Mohseni-Ejei compared women removing or refusing to wear the hijab in public to showing contempt for the Islamic Republic of Iran's system and its values.
Ejei added that removing the hijab violates public modesty, Islamic sharia rulings and Iranian law. He said that Iran's enemies abroad are encouraging the violations.
Women refuse to cover heads
Under Iran's Islamic sharia law, imposed after the 1979 revolution, women are obliged to cover their hair and wear long, loose-fitting clothes to disguise their figures. Violators have faced public rebuke, fines or arrest.
Following the wave of protests last autumn that plunged Iran into its most serious crisis in decades, many women are refusing to cover their heads, especially in bigger cities. At the same time, violations of the headscarf requirement are tracked by video surveillance.
The government has often turned a blind eye to the violation of hijab rule, but this has caused anger among pro-government clerics and politicians.