Iranian actress Taraneh Alidoosti has spoken out against her country's regime in a Instagram post to her six million followers.

"I fought for this dream for a long time and didn't want to accept it," she wrote.

"We are not citizens. We never were. We are captives. Millions of captives."

The 35-year-old, who starred in the Oscar-winning film The Salesman, made the statement a day [after protests broke out in Tehran](http://Iranians defy police for second night to protest over downed plane) over the 'unintentional' shooting down of a Ukrainian passenger jet, killing 176 people onboard.

Protests broke out in Tehran on Saturday after Iran's military admitted it shot down a passenger jet. Credit: AP

It was carrying mostly Iranians and Canadians, but Ukrainians, Swedes, Afghans and Brits were also on board, when it crashed.

Alidoosti posted her statement alongside a black square, which she said was to commemorate the hundreds of protesters killed by the Iranian regime in anti-government protests in November last year.

Videos posted online purport to show authorities firing tear gas and live ammunition on protesters in Tehran this weekend, but the government said there was no crackdown on protesters.

A protester comes face to face with a police officer in Tehran. Credit: AP

Alidoosti's statement comes days after Iran's only female Olympic medal-winning athlete, Kimia Alizadeh, announced she was defecting.

Posting on Instagram, the Taekwando 2016 bronze-medallist described herself as "one of millions of oppressed women of Iran".

Kimia Alizadeh after winning her bronze medal at the 2016 Rio Olympics Credit: AP

"They took me wherever they wanted. Whatever they said I wore. Every sentence they ordered I repeated... we are tools."

The sportswoman did not mention her plans but said she would always remain a "child of Iran".