Iranian women have previously engaged in anti-clerical establishment protests, but never before had they been the spark, leaders, and foot troops all at the same time. So far, more than two dozen people have been arrested, and three female demonstrators have been killed.

“I see a lot of fury and rage in young women,” said Golshan, 28, an Isfahan-based women’s rights activist who has gathered small groups of friends every night to scream, “No to hijab, no to slavery, only equal rights.”

For decades, Iranian women have fought against the rule requiring hijabs and long, loose robes that cover the body. The women’s rights movement has also lobbied — with limited success — against laws that made it easier for men to divorce than women, granted men exclusive custody of children, lifted restrictions on polygamy for men, lowered the marriage age for girls, and required women to obtain permission to travel from their husbands or fathers.But the current protests have spread far beyond the usual ranks of activists.

Every night, Nahid, a retired banker, said she provided sandwiches and first-aid kits for the marchers. Other ladies, she said, who were not actively involved, let demonstrators sleep in their homes to evade security forces and provided them with sweet drinks and pastries.

Activists say the response is the result of decades of quiet, grass-roots networking, even as major rights champions have been imprisoned or fled to exile.

In July, the president directed all “relevant authorities and institutions” to develop a plan to increase hijab enforcement. Violations, he claimed, were undermining the Islamic Republic’s beliefs and “supporting corruption.” Iran’s chief prosecutor stated his support for denying access to social and government facilities, including the subway, to women who were inadequately covered. The Ministry of Guidance instructed theaters to stop exhibiting women in advertisements. The idea has drawn criticism not only from the country’s secularists, but also from religious and conservative Iranians who say it will simply widen the gap between the government and its people.

The ecclesiastical elite, however, remained undeterred, blaming the reaction on foreign meddling. “In Islamic Iran’s history, the lives of Iranian women has always been synonymous with chastity and hijab,” Mr. Raisi remarked last month.

Several actresses also shared photos of themselves without a hijab on social media. Katayoun Riahi, one of them, was seen sans her headscarf in an interview with a Saudi-funded television program. On the evening of September 28, security officers allegedly stormed Riahi’s home. She was said to have left before they could apprehend her. Her present whereabouts is unknown. On September 29, the administrator of her Instagram profile cautioned that her life was “in danger.” Culture Minister Mohammad Mehdi Esmaili has previously stated that actresses who removed their veils in public would no longer be permitted to work in the nation.

“The hijab is a symbolic object that has pushed women to the fore,” said Nazli Kamvari, an Iranian-Canadian feminist novelist, “but also ties them to all kinds of oppression that everyone is suffering.”