One of Iran’s most popular female actors has bluntly criticised the government in Tehran in a post on Instagram, telling her almost 6 million followers that “we are not citizens” but “captives”.

Taraneh Alidoosti – who has appeared in an Oscar-nominated film and acclaimed TV dramas – made her comments on Sunday, as Iranians took to the streets in a series of anti-regime protests.

“I fought this dream for a long time and didn’t want to accept it. We are not citizens. We never were. We are captives,” she wrote.

Alidoosti said that she had replaced her profile picture with the colour black in mourning for demonstrators shot dead by security forces last November. The colour had nothing to do with official “mourning” following the assassination on 3 January of Iran’s top general Qassem Suleimani by a US drone, she added.

The actor’s intervention comes amid reports that Iranian authorities have fired live ammunition to disperse protesters in Tehran, wounding several people. The protests broke out after the government admitted on Friday its military had accidentally shot down a Ukrainian passenger jet, killing 176 people.

Alidoosti has previously spoken out against Donald Trump’s decision to impose visa bans on Iranians. In 2017 she boycotted the Oscar awards ceremony after The Salesman in which she starred was nominated in the best foreign language film category. The blanket ban was racist, she said.

She played the lead role in the film, directed by Asghar Farhadi. It is about a couple whose relationship is thrown into disarray after an intruder surprises her in the shower. Hardliners criticised Alidoosti after she returned from promoting the film at the Cannes film festival with a feminist tattoo on her arm.

Alidoosti also starred in a popular Iranian online TV series set in the 1950s, which has echoes in politics today. Shahrzad, the most expensive production of its kind in Iran, brought Iranian lifestyle under the late Shah to the screen, depicting snooker clubs, women and men partying together, cabarets and drinking alcohol.

She describes herself on her Twitter profile as an “actor, feminist, translator, mom”.