A woman raises her fist as she’s engulfed by a cloud from a smoke grenade during a protest at the University of Tehran on Dec. 30. (STR/AFP/Getty Images)

THE STREET demonstrations that erupted in Iran at the end of December appear to have faded for now, thanks in part to two dozen deaths and nearly 4,000 arrests by security forces. But there is plenty of evidence that deep discontent persists in the Islamic republic, along with the willingness to act on it. One inspiring example is the growing number of Iranian women who have perched on utility boxes and walls in the streets of Tehran, removed their legally required hijabs, or head coverings, and waved them on sticks.

The first to stage such a demonstration was a 31-year-old woman named Vida Movahed, who clambered onto a metal utility case on Enghelab, or Revolution, Street on Dec. 27. She took off her white headscarf, affixed it to a stick and silently waved it for an hour. Pictures and videos of her protest soon spread across the Internet, and other young women began to follow her example, both in Tehran and in other cities. They soon became known by the hashtag #GirlsofRevolutionStreet.

Predictably, the regime reacted to this mild and peaceful protest with repression. Ms. Movahed was arrested and held for several weeks before being released at the end of January. By Feb. 3, 29 women had been detained. A judiciary spokesman said some women, whom he claimed were “organized by ­foreign-based groups and [were] under the influence of industrial recreational drugs,” would be treated harshly. One activist arrested on Revolution Street on Jan. 30, Narges Hosseini, was imprisoned with bail set at more than $110,000.

Although the #GirlsofRevolutionStreet protests parallel the #MeToo movement in the West, they come in a uniquely Iranian context. Hijabs were banned during the repressive rule of the shahs, and during the 1979 revolution women wore them in protest. Now they are mandatory — Iranian police reported 3.6 million instances of hijab enforcement in 2014 — and so women are rebelling by taking them off. The point is not just rejection of a rotting authoritarian regime, but a demand by women for control over their own bodies.

Some in the government appear to recognize that, as with the street protests of December, the hijab wavers are part of wide current of popular discontent. This Last week the government of President Hassan Rouhani, a relative moderate, released a three-year-old report showing that nearly half of Iranians want to make hijab use optional. He has previously favored an easing of social restrictions, and in January was quoted as saying, “One cannot force one’s lifestyle on the future generations.”

As in so much else, however, Mr. Rouhani appears unwilling or unable to control the regime’s repressive apparatus, which continues to target any sign of dissent. That has only made Iranians more creative: According to opposition activists, many are expressing their anger by withdrawing their money from state banks. Spray-painted slogans calling for an end to the regime and death for its ruler, Ayatollah Ali Khamenei, appear first on walls, then in photographs posted to the Internet. In the past the regime has proved expert at crushing opposition movements. But the Girls of Revolution Street are one more sign that Iran has entered an unpredictable, and hopeful, season of ferment.