Two women have been arrested in Iran after they were attacked with a tub of yogurt while waiting in line in a store.

Viral footage shows a man approaching the women in the queue and talking to them.

He then grabs a container of yoghurt and dumps it onto the women’s heads, seemingly for not covering their hair in public.

The man is ejected from the store by the shopkeeper.

The BBC reports that Iran’s judiciary said the two women were later detained for showing their hair, which is illegal in Iran.

The man was also arrested for disturbing the public order while the shopkeeper was issued with “necessary notices” to ensure compliance with the law.

Women in Iran have been increasingly defying the compulsory dress code in protest since the death of Mahsa Amini, 22, while in the custody of the morality police last September.

The Kurdish woman had been detained for allegedly violating the hijab rule.

Since then government forces have been violently putting down months of nationwide revolt.

In a fresh warning, Iran’s judiciary chief has threatened to prosecute “without mercy” women who go unveiled.

Gholamhossein Mohseni Ejei’s warning comes on the heels of an Interior Ministry statement on Thursday that reinforced the government’s mandatory hijab law.

“Unveiling is tantamount to enmity with (our) values,” Ejei was quoted as saying by several news sites.

Those “who commit such anomalous acts will be punished” and will be “prosecuted without mercy”, he said, without saying what the punishment entails.

Ejei, Iran’s chief justice, said law enforcement officers were “obliged to refer obvious crimes and any kind of abnormality that is against the religious law and occurs in public to judicial authorities”.

Videos of unveiled women resisting the morality police have flooded social media.

Under Iran’s Islamic 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.

Still, women are widely seen unveiled in malls, restaurants, shops and streets around the country — risking arrest for defying the obligatory dress code.

Describing the veil as “one of the civilisational foundations of the Iranian nation”, the interior ministry statement on Thursday said there would be no “retreat or tolerance” on the issue.

It urged ordinary citizens to confront unveiled women. Such directives have in past decades emboldened hardliners to attack women without impunity.