Over 300 people have been killed in the unrest, according to foreign-based human rights groups.

Here is a timeline of the events:

- Sept. 13: Amini's arrest -

Amini is visiting Tehran with her family when she is detained by the Gasht-e Ershad (Guidance Patrols), the police unit that enforces strict dress rules for women, including the mandatory hijab or headscarf.

She is rushed to hospital later that day, with the police claiming she "suddenly suffered a heart problem". CCTV footage from the police station appears to show her collapsing.

- Sept. 16: death -

After three days in a coma, Amini is declared dead.

Rights activists say she suffered a fatal blow to the head while in custody, a claim echoed by a relative of Amini living in Iraq, but denied by officials.

President Ebrahim Raisi orders an inquiry.

- Sept. 17: first protests -

Amini is buried in her hometown of Saqez in the Kurdistan province of northwest Iran. Police use tear gas after some residents demonstrate.

In the following days, the hashtag #Masha_Amini clocks up more than one million tweets, including many videos of Iranian women cutting their hair in protest over her death and protests break out at several universities in Tehran.

- Sept. 20: first deaths -

Three people are reported killed during protests in Kurdistan province.

Videos posted on social media show women removing their veils and chanting "Woman, life, freedom" or "Death to the dictator", a slogan directed at Ayatollah Ali Khamenei, Iran's supreme leader.

- Sept. 22: social media muzzled -

Iran blocks access to Instagram and WhatsApp, the two apps most widely used in Iran, and imposes drastic restrictions on internet access.

The US places the morality police on its sanctions blacklist.

- Sept. 23: counter-demonstrations -

Thousands take part in pro-hijab counter-demonstrations in Tehran and other cities, in response to a call from the authorities.

On September 25, President Raisi vows "decisive action" to end the anti-hijab protests. A day later, more than 1,200 protesters are arrested.

- Oct. 3: Khamenei accuses US -

Khamenei accuses arch-foes the United States and Israel of fomenting the unrest.

- Oct. 8: death by illness -

An official medical report concludes Amini's death was caused by illness, due to "surgery for a brain tumour at the age of eight", and not police brutality.

Activists hack a state television live news broadcast, superimposing crosshairs and flames over an image of Khamenei.

- Oct. 15: prison blaze -

A fire erupts during clashes at Tehran's notorious Evin prison, where hundreds of those detained during the demonstrations over Amini's death are being held.

The blaze kills eight inmates, according to authorities.

- Oct 19: hero's welcome for climber -

Iranian sports climber Elnaz Rekabi receives an rapturous welcome on her return from the Asian Championships in Seoul, where she caused a stir by competing without a hijab, in a move widely seen as a gesture of solidarity with the anti-hijab protests.

- Oct. 26: mass rally in Amini's hometown -

Huge crowds pour into Amini's hometown to pay tribute at her grave to mark the end of the traditional period of mourning.

As protests break out, Iranian security forces open fire on the crowd.

- Nov 13: first death sentence -

A Tehran court hands down the first death sentence over the protests to a demonstrator accused of "corruption on earth", one of the most serious categories of crimes in Iranian law covering a wide range of offences.

- Nov 15: strike -

Protesters hold strikes and protests to mark three years since a deadly crackdown on unrest sparked by a fuel price hike in 2019 -- the last time Iranians took to the streets in big numbers.