Concern grew on Tuesday over the well-being of five young Iranian women who filmed themselves dancing without headscarves in a viral video, after allegations they had been arrested and forced into confessing.
The footage showed the women dancing with bare midriffs beneath highrises in the Tehran residential district of Ekbatan to the song "Calm Down" by Nigerian Afrobeats singer and rapper Rema.
It spread widely on TikTok and other social media channels last week around International Women's Day on March 8.
Activists, apparently from the Ekbatan area, first posted the video on Telegram and Twitter. They said authorities had been asking residents in the area if they knew the women, based on the footage.
On Tuesday the activists alleged the women had been detained and forced into making a video in which they expressed regret.
In the Islamic republic it is illegal for women to dance in public as well as to not wear the Islamic headscarf.
Abolition of the obligatory headscarf rule has been one of the chief demands of the protest movement that erupted in September after the death of Mahsa Amini, 22, who had been arrested for allegedly violating the dress code.
After the initial viral footage of the five, another video emerged on social media of four women, their heads fully covered, stepping forward one by one to express regret.
It appeared to have been filmed in a similar Ekbatan area, but neither the video nor the circumstances in which it was made could be verified.
Whether the women had been released was also not immediately clear.
Ekbatan, a middle-income area popular with young professionals and families, saw repeated anti-regime actions in the past few months.
Rema retweeted video of the women dancing with their long hair uncovered and commented: "To all the beautiful women who are fighting for a better world, I'm inspired by you, I sing for you and I dream with you."
The song "Calm Down" became a global hit after Rema issued a remix with superstar Selena Gomez.
The video also caught the attention of German Member of the European Parliament Hannah Neumann.
"On Women's day, they published this video. Wouldn't be worth news, but they danced in Iran," Neumann tweeted.
"The regime investigated, put them in prison, forced them into confessions and to wear hijab," she alleged.
During the protests hundreds of people have been killed, including dozens of security force personnel.
Thousands were arrested for participating in what Iranian officials described as "riots" and blamed on hostile forces linked to the United States, Israel and their allies.