Startled ultra-Orthodox Jewish men looked away as the group mounted a challenge to growing gender segregation in the holy city by boarding the public vehicle from the front door and sitting in its first rows.
As the male passengers averted their gaze, adhering to a traditional edict to avoid sexual temptation, a religious woman at the back of the bus shouted at the protesters: "Deal with the drugs, the crime and prostitution in your own communities first."
Buses and billboards, where some advertisers avoid posting images of women to avoid vandalization, have become the latest battlefields in the fight for the soul of Jerusalem, a city sacred to Jews, Muslims and Christians.
The boarding of bus 56, one of several segregated routes crossing ultra-Orthodox neighborhoods in the city, was the latest attempt by the Israel Religious Action Center (IRAC), to end separate seating.
"The new fad is to distance one's self from women as a way to measure piety. The idea that sex is dirty is not part of Judaism. We have to plug this leak before it spills over," said Anat Hoffman, IRAC's executive director.
But a religious woman on the bus, who gave her name only as Bracha, said there was no humiliation in sitting in the rear.
"It is a response to secular extremism. Look how their women parade along the beach in a degrading way," she said.
Black-garbed ultra-Orthodox Jews, known as "haredim," make up only about 10% of Israel's population of 7.7 million.
But their high birthrates and concentration in Jerusalem, where official figures show 26 percent of adult Jews consider themselves haredim, have stoked fears among the country's secular majority of religious interference in their lifestyle.
The concerns have also spread beyond the city. A group of Israeli generals wrote to the Defense Ministry on Monday saying the military must not give in to Orthodox demands to prevent the mixing of men and women in the ranks.
Nissim Hasson, vice president of sales at Zohar Hutzot advertising company, said ads showing women in Jerusalem are routinely vandalized.
When it comes to women on posters and billboards, he said, the holy city demands a different set of rules.
"Jerusalem is a symbol, a capital, built on mutual respect, holy to Jews, Christians and Muslims. If you want to be tolerant in this city you cannot advertize women," Hasson said.
Advertising its winter collection, an Israeli fashion company cropped out a female model's head and cleavage from a poster it put up in Jerusalem. In other Israeli cities, the full image ran.
The self-censorship prompted Uri Ayalon, a rabbi who is not a member of the ultra-Orthodox community, to start a Facebook campaign called "Uncensored" in which six women had their photos taken for 150 posters that were put up on Jerusalem billboards.
"We object to the sexist use of women in ads. But it is also important to me that my two daughters grow up in a place where they are not occluded because they are women," Ayalon said.
Tzaphira Stern-Assal, a secular mother of two who volunteered for the photo shoot, said she once put an ad for a dance class in the window of a dance school she runs, only to see it defaced the next day, along with posters of a dance group, with graffiti that read "Blasphemy."
Whenever the school's curtains are left more than a third open, Stern-Assal said, haredi men soon show up and start banging on the windows.
"It happens all the time," she said. "Do they want it to be everyone's city or just the haredim'? We want to live in dignity, not to be ashamed and hide behind curtains."
A sidewalk barrier to segregate the sexes went up last month in the Mea Shearim religious neighborhood of Jerusalem during the celebration of a Jewish holiday, mirroring the separation of men and women in Orthodox synagogues.
Secular activists who came to inspect the partition said they were chased away by residents, some of whom threw stones.
Rachel Azaria, a Jerusalem councilwoman, appealed to the Supreme Court against the barrier, which ordered it dismantled.
She was subsequently fired by Jerusalem Mayor Nir Barkat, in what political commentators called a nod to the ultra-Orthodox community's powerful punch in municipal elections.
"Segregation has been happening for a while. What's new is that the pluralistic public has woken up and is fighting. We won't stand it any longer," Azaria told Reuters.
She said a social change movement that swept through Israel in the summer, when hundreds of thousands took to the streets to demand economic reform, has emboldened those battling segregation.
"The public dares now to say its piece. The penny has dropped," she said.
Reliant on religious parties to help form governing coalitions, Israeli leaders have largely steered clear of cutting welfare subsidies to large ultra-Orthodox families, in which many of the men engage in religious studies full time.
Critics have pointed to the burden they put on the Israeli economy, but moves to cut the payments would spell political trouble for any of the country's major parties.
Addressing the religious-secular divide, the Supreme Court ruled this year that women traveling on public buses cannot be ordered to sit in the back.
Signs in Jerusalem buses now say people have a right to sit wherever they wish and that harassing passengers could be a criminal offense.
Critics say that in practice, dozens of bus lines are still gender segregated and that women who want to sit at the front are often subjected to verbal and sometimes physical assaults.
One haredi woman, who asked not to be identified, said she tried to buy a public transport pass in an ultra-Orthodox neighborhood in Jerusalem only to be turned away and told the ticket stand was for men only.
Her husband said they received threatening phone calls when word got out that they had lodged a complaint about the incident.
"Separation is important but in places where it makes sense, like the beach. Now there are calls for it on the light rail. There are segregated grocery shops and sidewalks. There's no basis for it in Jewish law and it's getting more extreme," he said.
Yakov Halperin, head of ultra-Orthodox Yehadut Ha Torah faction in Jerusalem's municipality, said people should stay out of the haredi community's business.
"If that's what they want, in their neighborhoods, they have the right to ask for it," he said.
"In Sodom and Gomorrah, which were annihilated because of the corrupt generation, there were those who kept the Torah's laws and put up fences in order to protect themselves," he said