Iran, where fresh pro-regime demonstrations took place Friday, has been rocked by days of opposition protests over the economy and the Islamic regime as a whole.

The unrest has left 21 dead, mostly demonstrators, and prompted hundreds of arrests. It is the biggest such movement in the tightly controlled country since a protest movement over a disputed election in 2009.

Here is a summary:

- First demonstrations -

A few hundred demonstrators gather in the northeastern city of Mashhad and several other towns on December 28 to protest high living costs.

Videos on reformist media show protesters focusing their ire on President Hassan Rouhani but there are also slogans lambasting the entire regime and Iran's involvement in conflicts across the Middle East.

The next day larger-scale protests flare up in more cities including religious centre Qom, where footage shows hundreds of demonstrators chanting "Death to the dictator" and "Free political prisoners".

- Warnings, violence, deaths -

On December 30, regime supporters rally around the country for officially sanctioned demonstrations to commemorate the defeat of the 2009 protest movement.

Despite government warnings, anti-government protests grow. Tear gas fills the streets of downtown Tehran as hundreds of people scuffle with police.

Videos show demonstrators attacking a town hall, overturning a police car and burning the Iranian flag.

The unrest claims its first victims when two people are killed in the western town of Dorud.

On December 31, the authorities issue more warnings and block access to online messaging services that were instrumental in organising protests.

Rouhani insists people are "absolutely free" to express their anger but "criticism is different to violence and destroying public property".

- Public buildings attacked -

Nevertheless the unrest continues as videos on social media show demonstrations across the country for a fourth night.

Iranian media and officials report 10 deaths in protests overnight Sunday to Monday in the west of the country.

US President Donald Trump says it is "time for change" in Iran.

- More deaths, arrests -

State television says nine people, including a policeman and Revolutionary Guards member, are killed in unrest on January 1.

Six die in the town of Qahderijan, in the central province of Isfahan, where protesters try to storm a police station, the state broadcaster reports. The number of arrests rises to 450.

- 'Enemies' -

Supreme leader Ayatollah Ali Khamenei breaks his silence on January 2, saying Iran's "enemies have united and are using all their means" against the regime.

Rouhani phones French leader Emmanuel Macron to demand action against a "terrorist" Iranian opposition group he accuses of fomenting the protests, likely referring to the Paris-based Mujahedeen-e-Khalq.

The French president calls for restraint.

- End of 'sedition' -

On January 3 the commander of the elite Revolutionary Guards, General Mohammad Ali Jafari, announces "the end of the sedition".

At the United Nations, Iran accuses Washington of "grotesque" meddling.

On January 4, the United States imposes sanctions on five Iranian companies it alleges are working on Iran's illegal ballistic missile program.

- New pro-regime demonstrations -

On January 5 pro-regime rallies are held around Tehran for the third day running.

Prosecutor Mohammad Jafar Montazeri accuses the United States, Israel and Saudi Arabia of being behind the violence. His deputy criticises the government for not having blocked the internet.

Iranian officials say they have arrested four members of a "terrorist cell" linked to the Mujahedeen.

In the evening the UN Security Council holds closed-door talks on Iran -- before starting a formal meeting -- with Russia and the United States at odds over whether the top UN body should discuss the demonstrations.