A demonstrator holds a photo of Mahsa Amini during a protest outside the Iranian Embassy in Nicosia, Cyprus, on Tuesday. Amini died after being arrested by Iran's morality police for allegedly violating its strictly enforced dress code. (Philippos Christou/The Associated Press)

Iranian riot police and security forces clashed with demonstrators in dozens of cities on Tuesday, state media and social media said, amid continuing protests over the death of a young Iranian woman in police custody.

Mahsa Amini, 22, from the Iranian Kurdish city of Saqez, was arrested earlier this month in Tehran for "unsuitable attire" by the morality police who enforce the Islamic Republic's strict dress code.

She died three days later in hospital after falling into a coma, sparking the first big show of opposition on Iran's streets since authorities crushed protests against a rise in gasoline prices in 2019

Despite a growing death toll and a fierce crackdown by authorities using tear gas, clubs and, in some cases, live ammunition, videos posted on social media showed protesters calling for the fall of the clerical establishment while clashing with security forces in Tehran, Tabriz, Karaj, Qom, Yazd and many other Iranian cities.

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State media branded the protesters "hypocrites, rioters, thugs and seditionists," while state television said police clashed with "rioters" in some cities and fired tear gas to disperse them.

Videos posted on social media from inside Iran showed protesters chanting, "Women, life, freedom," while women waved and burned their veils and cut off their hair.

People participate in a protest in New York City on Tuesday. Amini's death in police custody has sparked demonstrations in Iran and worldwide. (Stephanie Keith/Reuters)

Videos on Twitter showed protesters chanting "Death to the dictator," a reference to Iran's top authority Supreme Leader Ayatollah Ali Khamenei. In the Kurdish cities of Sanandaj and Sardasht, riot police fired at protesters, Twitter videos showed.

"I will kill those who killed my sister," chants of protesters could be heard in one of the videos from Tehran, while activist Twitter account 1500tasvir said: "The streets have become battlefields."

The videos and statements on social media could not be verified by Reuters.

Further videos on social media showed protests continuing in dozens of cities after nightfall on Tuesday. "Continuing shootings can be heard in Chabahar, Sistan and Baluchestan," 1500tasvir said on Twitter.

State media also reported the arrest of women's rights activist Faezeh Hashemi Rafsanjani, the daughter of a former Iranian president and founder of the Islamic Republic, for "inciting riots" in Tehran.

To make it difficult for protesters to post videos on social media, authorities have restricted internet access in several provinces, according to Internet blockage observatory NetBlocks and sources in Iran.