Iranian authorities detained a young female singer for performing without a mandatory hijab in a concert held up as an act of resistance.

Parastoo Ahmadi, 27, was arrested on Saturday in the northern city of Sari, after live-streaming wearing a dress that exposed her shoulders.

Ms Ahmadi performed without an audience in the courtyard of a caravanserai, broadcasting the concert live on her YouTube channel, despite the platform being banned in Iran.

Her lawyer said the arrest was carried out without prior notification or judicial summons. Milad Panahipour added that she was released at 3am local time on Sunday.

In a sign of the regime’s growing nervousness over protests, her lawyer said she was released following widespread outrage over the news of her arrest.

Ms Ahmadi said singing for the people she loves is a right she cannot ignore, making her the first and only female Iranian singer to perform publicly without a hijab since the 1979 Islamic Revolution.

‘For my dear people’

Women are not allowed to sing solo in public under the clerical regime’s laws in Iran.

On her Instagram page, she described the concert as being “for my dear people, carried out under difficult conditions and high tension,” calling it “imaginary”.

She wrote, “I am Parastoo, a girl who wants to sing for the people I love. This is a right I could not ignore - singing for the land I passionately love. Here, in this part of our dear Iran, where history and our legends intertwine, listen to my voice in this imaginary concert.”

Her Instagram page has been inaccessible since her arrest.

She sang nine popular Persian songs, including one frequently played at protest gatherings over the past few decades.

Lyrics included: “From the blood of the young people of the homeland, tulips have bloomed, 

“From the mourning of their tall stature, the cypress has bent.

“What a bad behaviour, O life. What a wrongdoer you are, O life, 

 “You hold a grudge, O life, you have neither faith nor principles, O life.”