A young woman has died after falling into a coma following her detention by Iran’s morality police, state media have reported, sparking fury on social media.

Mahsa Amini, 22, was on a visit to Tehran with her family when she was detained by the specialist police unit that enforces the strict dress code obligatory for women since shortly after the Islamic revolution of 1979.

“Unfortunately, she died and her body was transferred to the medical examiner’s office,” state television reported on Friday. The announcement came a day after Tehran police confirmed Amini had been detained with other women for “instruction” about the rules.

“She suddenly suffered a heart problem while in the company of others receiving guidance [and] was immediately taken to hospital with the cooperation of the emergency services,” it said.

President Ebrahim Raisi ordered the interior minister to open an inquiry into the case.

Several lawmakers said they would raise the case in parliament, while the judiciary said it would form a special task force to investigate.

Reacting to the incident, human rights organisation Amnesty International said, “The circumstances leading to the suspicious death in custody of 22-year-old young woman Mahsa Amini, which include allegations of torture and other ill-treatment in custody, must be criminally investigated.”

“The so-called ‘morality police’ in Tehran arbitrarily arrested her three days before her death while enforcing the country’s abusive, degrading and discriminatory forced veiling laws. All agents and officials responsible must face justice,” it added.

Amini’s death comes amid growing controversy both inside and outside Iran over the conduct of the morality police, known formally as the Gasht-e Ershad (Guidance Patrol).

In July, a video of a woman standing in front of one of the forces’ vans pleading for her daughter’s release went viral on social media. The veiled woman kept holding on to the van as it pulled off, only being thrown clear after it gathered speed.

The mandatory dress code, which applies to all nationalities and religions, not just Iranian Muslims, requires women to conceal their hair and neck with a headscarf.

Over the decades, women have increasingly pushed back, particularly in the big cities, wearing their headscarves far back on their heads to reveal their hair.

Since 2017, after dozens of women publicly took off their headscarves in a wave of protests, the authorities have adopted tougher measures.

Iran’s supreme leader, Ayatollah Ali Khamenei, has supported a softer attitude towards women who do not comply with the official dress code. But hardliners have called for harsh punishment and even lashes, arguing that allowing women to show their hair leads to moral decay and the disintegration of families. The judiciary has in recent years urged people to inform about women who do not wear the hijab.

Amini’s case has drawn condemnation from Iranian celebrities, athletes and other public figures.

The pro-reform former President Mohammad Khatami said the behaviour of the morality police was a “disaster”, while outspoken politician and former lawmaker Mahmoud Sadeghi called on Khamenei to speak publicly about Amini’s case.

“What does the Supreme Leader, who rightfully denounced US police over the death of George Floyd, say about the Iranian police’s treatment of Mahsa Amini?,” Sadeghi said on Twitter.

Former footballer Ali Karimi tweeted that while children of high-ranking officials are leaving the country, “our children are dying”.

Hossein Mahini, another former footballer, said in a tweet, addressing the morality police: “We hate you.”