Amnesty International is demanding the release of a university student who it claims was "violently arrested" after stripping off, reportedly in protest against Iran's strict Islamic dress code.
The human rights organisation has tweeted to claim the unidentified woman was demonstrating at the "abusive enforcement of compulsory veiling by security officials at Tehran's Islamic Azad University".
Sky News cannot verify the circumstances of what happened in Iran's capital on Saturday, but footage posted online showed a woman stripped to her underwear and walking outside the campus.
University officials issued a statement saying the woman was "under severe stress and suffering from mental disorders, and has been transferred to a medical centre".
Masih Alinejad, a prominent Iranian activist, gave a different account. In a message on X, she said a student "harassed by her university's morality police over her 'improper' hijab didn't back down".
"She turned her body into a protest, stripping to her underwear and marching through campus - defying a regime that constantly controls women's bodies," she added.
Videos on social media appear to show the woman being arrested and placed in a car.
A statement from Amnesty said: "Iran's authorities must immediately and unconditionally release the university student who was violently arrested on 2 November".
According to the Iranian Students' News Agency (ISNA), financially supported in part by the Iranian government, the student was not challenged about the wearing of a hijab.
Under Iran's strict Islamic dress code, women must wear a headscarf in public.
The ISNA released a statement describing a "brief argument" with university security officials about using her mobile to film other people without their permission.
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Mai Sato, the United Nations special rapporteur on Iran, said on X: "I will be monitoring this incident closely, including the authorities' response".
Despite widespread protests following the death of Mahsa Amini in 2022 while in police custody over hijab violations, Iran has continued to enforce strict dress codes for women.