France's president Emmanuel Macron has condemned anti-Semitic abuse hurled at an eminent French philosopher in Paris.
A small group of "yellow vest" ("gilets jaunes") demonstrators accosted Alain Finkielkraut during Saturday's protests in the French capital.
They shouted: "Go back to Tel Aviv!", "We are France!", and "Zionist!".
A senior member of the "yellow vest" movement said on Sunday he strongly denounced the remarks made to Finkielkraut.
Finkielkraut, the son of a Polish Auschwitz survivor and a vocal supporter of Israel, is a prominent intellectual and member of the Académie Française, who frequently appears on talk shows.
He had shown sympathy for the "yellow vests" movement but also criticised it in a recent interview with Le Figaro newspaper.
Macron, posted on Twitter, wrote: "The son of Polish immigrants who became a French academic, Alain Finkielkraut is not only an eminent man of letters but a symbol of what the republic allows for everyone."
He added: "The anti-Semitic insults he has been subjected to are the absolute negation of who we are and what makes us a great nation. We will not tolerate them."
The president's was among a chorus of tweets, with Interior Minister Christophe Castaner denouncing "the surge of pure hate", while government spokesman Benjamin Griveau tweeted that "the ugly beast lurks in the anonymity of the crowd".
One of the organisers of a "yellow vests" march in Paris on Sunday said he "strongly" denounced the anti-Semitic remarks made to Finkielkraut.
Bruno Mandres said that "those who did that are not real gilets jaunes" and that he feared the movement will be wrongly portrayed.
"I completely denounce the acts carried out yesterday, because those who did that are not real Gilets Jaunes. It's a pity because now we will be treated as anti-Semites. That's not true. One cannot agree with his [Finkielkraut's] ideas. I am totally against that person [Finkielkraut], but that is not a reason to insult him. I denounce it. I am sad about it."
Paris authorities opened an investigation on Sunday into the incident – classed as a "public insult based on origin, ethnicity, nationality, race or religion" – although speaking to the newspaper Le Parisien, Finkielkraut said that he would not press charges.
The incident has raised national concerns about the ascendant radical fringe of the increasingly divided "yellow vests" movement, which began as protests against a fuel tax hike and broadened to include a range of concerns about France's living standards and the economic issues facing ordinary families, as well as a perceived lack of regard for such issues among the ruling political elite in Paris.
Some "yellow vests" have expressed racist or anti-Semitic views online and on the sidelines of protests. Recent figures indicate a resurgence of anti-Semitism in France, with a 74% rise in incidents recorded across the country last year.
In the last week, swastikas have been drawn on portraits of the late Holocaust survivor and politician Simone Veil, and a Paris bagel shop was spraypainted with the word “Juden” (German for “Jews”), while a tree planted in memory of murdered Parisian Ilam Halimi was found chopped down.
Hilami was a young Jewish man who was kidnapped and tortured to death in 2006 by a Muslim gang, who demanded a huge ransom from Hilami's family, assuming they were rich because they were Jewish.
Meanwhile, protesters have been marking the movement's three-month anniversary at rallies in Paris and around France. Saturday's marches marked the 14th straight weekend of demonstrations, which began on November 17.
While most French people initially supported the "yellow vests", a poll last week indicated for the first time since the movement began that the majority – 58% – now want to see an end to the protests.