Iranian authorities said on Monday that the death of a young woman in the custody of the morality police was an “unfortunate incident”.
“This incident was unfortunate for us and we wish to never witness such incidents,” Greater Tehran Police Commander Hossein Rahimi said in a statement reported by the Fars news agency.
Iranians took to the streets of the capital Tehran on Monday to protest Amini's death.
Students in many of the city's universities gathered in protest, demanding an investigation and the dismantling of the morality police, who were holding her when she died, Iran's semiofficial Fars news agency.
Under Iran’s laws, women are obliged to cover their hair and wear long, loose-fitting clothes. Offenders can face public rebuke, fines or arrest.
But in recent months activists have urged women to remove veils, despite the hardline rulers' crackdown on “immoral behaviour”.
Mr Rahimi said Amini suffered no mistreatment, denying claims made on social media against the moral police.
“Cowardly accusations have been levelled against the Iranian police. We will wait until the day of judgment but we cannot stop doing security work,” Mr Rahimi said. He added that the moral police were “doing positive work”.
He said he could not comment on the cause of death because this was a medical rather than a security issue.
‘No health problems’
But Amini's father told the pro-reform Emtedad news website on Sunday that his daughter was fit and had no health problems, Reuters reported.
“Authorities have said my daughter suffered from chronic medical conditions. I personally deny such claims as my daughter was fit and had no health problems,” he was quoted as saying.
Amini was from the country's Kurdistan province, one of the areas where protests took place at the weekend, including at the funeral in her home town Saqez.
Between eight and 10 million Kurds live in Iran. Iran’s Islamic Revolutionary Guard Corps has put down unrest in the country’s Kurdish areas for decades.
Meanwhile, there were reports about more protests on Sunday and #MahsaAmini became one of the most popular hashtags to date on Persian-language Twitter.
Iranian activists outside Iran have urged women to remove headscarves and cut their hair in solidarity with Amini.
On Sunday, Iranian journalist and human rights activist Mashih Alinejad posted footage of what she described as a protest in Tehran University in solidarity with Amini. The National could not authenticate the footage.
The young woman was laid to rest on Sunday in her home town.
Reports suggested that some angry protesters marched towards the local governor's office to protest about the death.
The BBC Persian Service reported Sunday that it had verified videos showing security forces opening fire on protesters.
The internet connection has been disrupted in various locations in Iran since news of Amini's death came out, Netblocks, a watchdog organisation that monitors internet governance, tweeted on Saturday.
Many users said they could not upload videos on Instagram or send content over WhatsApp.