They were sparked by the death of Mahsa Amini after her arrest by the morality police and have been led by women burning headscarves and furiously demanding reform in the Islamic Republic of Iran. But the protests that have engulfed the nation for weeks are also attracting support from across society as they evolve into a sustained anti-government movement.
While women and girls continue to be the driving force behind the protests, male students, soccer stars and striking workers have added to this show of opposition. This sort of coalition will make it harder for state authorities to suppress in spite of a violent crackdown, experts say.
"These are not pockets of protests," said Anoush Ehteshami, a professor in international relations at Durham University in England. "This time, around 80 towns and cities have been involved. And it's so broad-based, and a lot of it is spontaneous."
Students in the capital, Tehran, and other major cities refused to attend classes Saturday on what was meant to be the first day of the new university semester, according to verified accounts on social media and local reports.
Instead, male and female students were seen marching on campus grounds or gathered in crowds, with some heard chanting "Women, life, freedom," in protests against the government and its violent crackdown on weeks of rallies triggered by the death of Amini last month, according to video posted on social media and reviewed by NBC News.
In footage shared by the New York-based Center for Human Rights in Iran, a group of young Iranian girls are seen removing their hijabs while chanting anti-government slogans.
NBC News was unable to independently verify the video.
There were student-led protests in the cities of Tehran, Tabriz and Shiraz, according to video on social media. Also Saturday, shops and businesses were closed in 20 cities in strike action in Kurdistan province, in northwestern Iran, according to the human rights organization Hengaw.
Amini, 22, who was from the region, died Sept. 16 after falling into a coma following her detention by morality police in Tehran, who enforce the government's strict dress codes for women.
Police deny allegations that Amini was beaten and insist that she died after suffering a heart attack. Iranian President Ebrahim Raisi, a hard-liner, has since ordered an investigation into her death and said he offered his condolences to her family. Her family denies that she had a pre-existing condition and says witnesses told them she had been beaten by police.
The government has blamed what it calls "foreign enemies" for stoking the unrest. On Monday, Iran's supreme leader Ayatollah Ali Khamenei broke his silence on the unrest and accused the United States and Israel of planning the protests.
So far, 41 people have died in the demonstrations, Iranian state TV said last week, although human rights groups estimate this number to be much higher.
NBC News has not been able to independently verify the number of those who have died during the protests.
Outside Iran, social media users have cut their hair in solidarity, while thousands have attended rallies in European capitals and American cities like Los Angeles. The Iranian men's soccer team held its own silent protest before a game in Austria last week, wearing black jackets that covered their national team emblem.
Analysts say that these signs of a broader movement could prove a potent force that would be harder for the government to quash.
"There have been strikes before," but this movement is "carried by outrage and an incredible amount of anger at the Iranian government and its inability to reform," said Arshin Adib-Moghaddam, a professor in global thought and comparative philosophies at the School of Oriental and African Studies in London.
"There are also social and gendered dynamics at play, as the protests are clearly carried by Iranian women, both within the country and outside," he added.
Despite the scale and longevity of the protests, there is no evidence yet of any clear structure or leadership. Neither have any notable political figures been involved, except for Faezeh Rafsanjani, the daughter of former President Akbar Hashemi Rafsanjani, who was a reformist.
Iranian state media reported Thursday that she was arrested after taking part in the protests and charged with "inciting riots," according to Reuters.
The government has not commented on the arrest.
This lack of public leadership is in contrast to the mass protests in 2009, which developed into what became known as the Green Movement and coalesced around the presidential candidate Mir Hossein Mousavi, who challenged the result of that year's election.
On Saturday, Mousavi, who has been under house arrest in Tehran since 2011, issued a statement in support of the demonstrators.
Any potential leadership is most likely to come from Iran's unofficial unions, said Peyman Jafari, a historian at the College of William and Mary in Virginia. "If that happens, then it is going to be a considerable force that can really paralyze the state with strikes," he said.
Strikes that began in Iran's oil fields in 1978 soon spread across other sectors nationwide, with workers from almost every major industry walking off their jobs.
The industrial action, together with months of public protests, crippled the country and helped to bring about the eventual downfall of the powerful Shah Mohammad Reza Pahlavi, paving the way for the Islamic Revolution soon after.
Although there has been unrest more recently in Iran, such as the one following the disputed presidential election in 2009 and another over the cost of living in 2019, experts say the current protests may be helped, rather than held back, by the absence of a formal movement.
But the state, which drew a show of support from lawmakers chanting "thank you, police" during a parliamentary session Sunday, is not unprepared.
"The problem is that the government has been very wary about the role of these unions and workers, so therefore it has arrested and repressed their leaders," Jafari said.
This article was originally published on NBCNews.com