PARIS (Reuters) - Leaders of the far-right National Front and hard-left France Unbowed movement met booes on Wednesday when they joined a march in honor of a Holocaust survivor killed in a suspected anti-Semitic attack and were eventually forced to leave it.

An official holds a white rose as he attends a gathering, organised by the CRIF, in memory of Mireille Knoll, in Paris, France, March 28, 2018. REUTERS/Gonzalo Fuentes

The National Front’s Marine Le Pen and France Unbowed’s Jean-Luc Melenchon had defied a prominent Jewish group’s wishes by taking part in the march to honor Mireille Knoll.

The 85-year-old was found dead with 11 stab wounds at her apartment in a working-class district of Paris on Friday. The apartment was set ablaze after the attack and her body badly burnt. Police suspect that Knoll’s Jewish religion was a motive for the killing.

Le Pen and Melenchon joined the march but they met a hostile reception from participants and when tensions threatened to boil over they pulled out. Le Pen later managed to rejoin the demonstration.

Knoll was buried on Wednesday in Bagneux on the southern outskirts of Paris ahead of the march organized by Crif, an umbrella body of French Jewish groups. Crif’s leader told far-right and far-left groups not to attend the rally.

“Anti-Semites are over-represented in the far left and the far right, making those parties ones that you don’t want to be associated with,” Crif director Francis Kalifat told RTL radio. “Therefore they are not welcome.”

His comments underscore the enduring alarm among France’s 400,000-strong Jewish community over anti-Semitism, which Interior Minister Gerard Collomb on Tuesday described as a cancer that must not be allowed to eat away at the nation.

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“We’ve got our place here. Once again (the Crif) have got the wrong enemy. We’ve been fighting Islamist anti-Semitism for years,” Le Pen said defiantly despite the hostile reception she received.

Other marches were held in Lyon, Marseille and Strasbourg.

Le Pen has strived to rid the party of the toxic anti-Semitic reputation it gained under her father, party founder Jean-Marie Le Pen.

However, France’s highest court provided a reminder of the party’s past on Tuesday when it upheld the conviction of her father for describing the Nazi gas chambers as a “detail” of history. It confirmed a 30,000 euro ($37,000)fine against him.

Israel’s Foreign Ministry condemned Knoll’s murder and said it “underlines the need to continue combating anti-Semitism in all its variations”.

Knoll escaped being deported to Auschwitz during World War Two, when 13,000 Jews were rounded up in July 1942 in the capital’s Velodrome d’Hiver.

Her son Daniel said the rally should be open to everyone.

“Crif is playing politics but I’m just opening my heart,” he told RMC radio.

President Emmanuel Macron’s government said the rally should be a moment for national unity.

Macron made reference to Knoll’s death in a national tribute to a gendarme killed last week in an Islamist attack. The president said Knoll was murdered “because she was Jewish”, by a killer who did not value life.