For some French Jews, Saturday's unrest brought an unsettling warning: conceal outward signs of Jewish identity and avoid gathering outside synagogues.

One community member told Fox News Digital that some congregations had even canceled afternoon prayers on the Sabbath as demonstrations across France descended into violence.

Ahead of the protests on Saturday, he said, as a precaution, "Lots of synagogues sent out emails to their people saying, 'We're canceling Mincha on Shabbat afternoon. Please don't go out. It's going to be dangerous,'" Samuel Arrouas, a French Jewish community member who divides his time between Paris and Israel, told Fox News Digital.

Mincha is the Jewish afternoon prayer service. Arrouas, who returned to Israel before Saturday's protests, described his shock over the messages. "I'm 40-years-old. First time I heard this," he said.

Arrouas said warnings also advised Jews against visibly wearing kippahs, traditional skullcaps, or tzitzit, ritual fringes worn by observant Jewish men. Worshipers were discouraged from lingering outside synagogues after services. "You go to prayers, and you immediately leave," he said.

Before leaving France, Arrouas said he encountered masked demonstrators carrying Palestinian flags near Paris Dauphine University.

"It's very scary," he said. "When you're Jewish and you pass in front of such a scene, the only thing you want to do is just get away." The concerns emerged as approximately 550,000 people demonstrated across France on Oct. 17 against rising fuel prices, the cost of living and deteriorating public services, including schools. The demonstrations were masked rioters clashed with police, looted businesses and set fire to vehicles and buildings in Paris, Marseille and other cities. France's Interior Ministry reported approximately 2,400 arrests.

President Emmanuel Macron called for "calm and order" in a national address, warning against escalation. "We all feel anger and shame," he said, distinguishing protesters' "legitimate demands" from "those who destroyed, smashed and looted." He said "nothing justifies" the violence and pledged accountability. Interior Minister Laurent Nuñez offered his resignation, which Macron refused.

Shannon Seban, the France-based executive director of European affairs at the Combat Antisemitism Movement, said the presence of Palestinian flags at demonstrations over domestic issues added to Jewish community concerns.

"We have seen Palestinian flags at demonstrations that were supposed to be about education and social demands. What does Gaza have to do with any of this?" Seban told Fox News Digital.

"This has nothing to do with legitimate student demands anymore. We are talking about organized violence, about people who are not coming to demonstrate but to destroy, to attack our police officers and to challenge the authority of the Republic," she said.

Seban linked the violence to rhetoric urging people to "globalize the intifada" and to antisemitic conspiracy theories circulating online.

"At the Combat Antisemitism Movement, we documented 1,384 antisemitic posts in just two days, including conspiracy theories accusing Jews and Israel of being behind the unrest," Seban said.

"The right to protest is fundamental in a democracy. But the right to protest is not the right to destroy," she added. "France and Europe must wake up. Before it is too late." In Marseille, Bruno Benjamin, president of the Marseille-Provence branch of CRIF, the Representative Council of French Jewish Institutions, described the damage to local businesses and the anxiety facing the community.

"Several hundred shops were ransacked, vandalized, and looted. The scale of the devastation is simply unbearable," Benjamin told Fox News Digital.

He said shopkeepers had seen years of work destroyed within hours, leaving some facing layoffs or temporary unemployment for employees.

"This is not just an attack on businesses. It is an attack on people's livelihood, their dignity, and the very fabric of our society," he said.

France's Jewish community security organization, SPCJ, cautioned against assuming that Jewish-owned property was targeted because of religion. In a statement provided to Fox News Digital, SPCJ said a break-in and vandalism at a synagogue in Paris's 19th arrondissement initially suggested burglary, although the motive remained undetermined. Jewish-owned businesses were among those damaged in Marseille, it said, without evidence they had been singled out for being Jewish.

The U.S. State Department's existing Level 2 travel advisory urges Americans to exercise increased caution in France because of terrorism and unrest. Fox News Digital reached out to the French Embassy in Washington, D.C., for comment on the unrest and the safety of the Jewish community.

Benjamin said rising insecurity and antisemitism had left some French Jews considering whether to leave the country, while others remained determined to stay.

"We must relentlessly combat antisemitism, defend their right to live in safety and dignity and ensure that no Jew in France should ever have to choose between their personal security and their love for their country," he said. "Because being Jewish in France should never mean having to live in fear."

For Seban of the Combat Antisemitism Movement, it's evident where the blame lies: "Let me be very clear: La France Insoumise and the far left bear a political responsibility for fueling this climate of violence and confrontation."