In Paris, a handful of so-called "yellow vest" protesters on Saturday hurled anti-Semitic slurs at noted French philosopher Alain Finkielkraut.
President Emmanuel Macron tweeted that "the anti-Semitic injuries he received are the absolute negation of what we are and of what makes us a great nation. We will not tolerate it."
"The son of Polish immigrants who became a French academician, Alain Finkielkraut is not only a prominent man of letters but the symbol of what the Republic allows everyone," the French resident added in another tweet.
Macron's was among a chorus of tweets, with Interior Minister Christophe Castaner denouncing "the surge of pure hate," while government spokesman Benjamin Griveaux tweeted that "the ugly beast lurks in the anonymity of the crowd."
The leader of the Republicans opposition party, Laurent Wauquiez, denounced the "abject idiots."
Ian Brossat, chief French Communist Party candidate for the European Parliament, said "We can hate Finkielkraut's ideas," but "nothing can justify attacking him as a Jew".
The insults included phrases like "Dirty race!" "Dirty Zionist!" and "Go back to Tel Aviv!" and "France is ours!"
Finkielkraut, 69, once showed sympathy for the movement but criticized it in a recent interview with Le Figaro daily. Some yellow vest protesters have expressed racist or anti-Semitic views online and on the sidelines of protests.
"I felt absolute hatred and, unfortunately, this is not the first time," Finkielkraut told the Sunday paper Le Journal du Dimanche. He expressed relief that police intervened.
"I would have been afraid if there had not been the police. Fortunately, they were there," he told the newspaper, while adding that not all the demonstrators were hostile towards him and one even suggested he put on a vest and join the prowwww.
A best-selling author, in 2016 Finkielkraut entered the pantheon of French academia when he was admitted into the Académie française, which is a council of 40 greats elected for life.
A recent spate of anti-Semitic vandalism and graffiti in and around Paris has stoked fresh concerns about an increase in hate crime against Jews.
Fourteen political parties last Thursday launched a call for action against anti-Semitism after the interior ministry reported a 74% increase in anti-Jewish acts last year.
The yellow vest protests began three months ago over fuel taxes but quickly grew into a broader anti-government rebellion fueled by hatred of Macron, with some using anti-Semitic tropes to refer to his former job as an investment banker.
French media quoted the Interior Ministry as saying that 41,500 protesters nationwide turned out Saturday, some 10,000 less than the previous week, with 5,000 in Paris.
"No social peace without equitable sharing. … The people aren't a milk cow," was the message scrawled on a wooden cross, carried by a protester dressed in monk's garb.
Police fired tear gas and brought in water cannons and a horse brigade to disperse the protesters massed near a Paris landmark at the end of a march through the French capital, the 14th straight weekend of demonstrations.
The Paris prosecutor's office said 15 people were detained for questioning, far less than the scores detained in earlier, larger demonstrations that degenerated into scattered rioting and destruction.
Tension also marked demonstrations in other cities.
In Rouen, in Normandy, a car blocked by demonstrators pushed through the crowd, slightly injuring four people, the all-news channel BFMTV reported. Police used tear gas and water cannon in Bordeaux, a stronghold of the yellow vest movement. Another demonstration in the capital was planned for Sunday to mark three months since the movement held its first nationwide protests Nov. 17.
The increasingly divided movement, however, is having trouble maintaining momentum and support from the public that initially massively backed protesters, polls showed.
Many French are asking aloud how long the yellow vest movement will keep up its protests, which drain security forces and have dented the French economy.
Emilie Bidois, from the Normandy town of Gisors, who was taking part in the Paris protest, admitted she was growing tired – but remaining determined.
"We're fed up but we won't give up. We won't give up on anything because they want to muzzle us and we want to be heard," she said. "I will carry on until the movement runs out of steam, if it runs out of steam, but I don't think it will."
Leo Peyrade, a 70-year-old Parisian, referred to the violence that has hit numerous protests, often triggered by small extremist groups, and said he has learned to be careful. Last week, a young protester lost four fingers from a grenade. Others have lost eyes.
"Every time I come, some are wounded, arms, legs. I'm careful," he said. "I can't run like a young person, not as fast in any event."
