(CNN) Iranian women have been taking off their headscarves in public places to protest the law that forces women to wear the veil in public.
Powerful images have appeared on social media of a number of women, their heads uncovered, holding their hijabs on the end of sticks and standing on utility boxes on street sidewalks.
The protests have spread since Vida Mohaved, a woman who was arrested in December by Iranian authorities after removing her headscarf during a wave of anti-regime protests, was freed on Sunday.
The social media posts have been using the hashtag "The girls of Revolution Street," a tribute to Mohaved, whose original protest took place on the Tehran city center thoroughfare, also known by its Farsi name, Enghelab Street.
In recent months, enforcement of the law -- first enacted after the Islamic Revolution in 1979 -- has been relaxed. In the past, women who allowed their hijab to slip could be admonished by the religious police, but these forces have been less prominent under the regime of President Hassan Rouhani.
Authorities also announced that women driving with improper head coverings would no longer be arrested, and instead receive a relatively small fine.
The easing of the enforcement has emboldened younger women to become more defiant, but recent incidents where they have removed their hijabs in protest could still lead to prison sentences.
Iranian human rights lawyer Nasrin Sotoudeh told CNN that an "official with the judiciary" and relatives had confirmed to her that detained woman had been released.
Sotoudeh told CNN that Mohaved was in jail for more than 30 days, but there has been no official confirmation of the detention.
"I am happy that she returned to her home yesterday. I hope that, by creating a judicial case against her, they do not harm her just because she has exercised her basic and inalienable right(s)," a Facebook post by the lawyer reads.
"She has done nothing and does not deserves to be pursued by the judiciary. Keep your hands off of her."
Mohaved attracted attention during countrywide protests last month, which sprang up in opposition to faltering economic conditions, corruption and a general dissatisfaction with the government.
A video of Mohaved standing on a utility box, her black hair flowing and her white hijab defiantly hanging from the end of a pole, was posted online.
The video gained momentum during the Iran protests on Twitter, alongside a social media campaign called #whitewednesdays against the law forcing women to wear the hijab.
In mid-January, more than 400 people detained in the anti-government protests were released, state-run media reports.
Twenty-one people died and an unknown number were detained during six days of demonstrations, which were the biggest challenge to the Iranian regime since 2009.
Lawmaker Mahmoud Sadeghi claimed that roughly 3,700 people had been arrested in total. That number is far higher than the 450 people Iranian authorities previously said were detained after protests began December 28. US officials had put the number held at 1,000.