(JTA) — Supporters of the anti-Semitic comedian Dieudonne hijacked three French pro-Israel websites in a coordinated cyber attack.

The attack Thursday paralyzed the websites Israel-Flash.com, Europe-Israel.org and liguedefensejuive.com, the website of the French Jewish Defense League, and replaced their content with messages of support for Dieudonne, Le Nouvel Observateur reported.

On the hijacked websites, the hackers called the attack a “triple quenelle” — a reference to a gesture invented by Dieudonne, which French Interior Minister Manuel Valls last week termed “an inverted Nazi salute, an anti-Semitic gesture of hate.” The gesture involves placing one’s outstretched left palm on one’s right shoulder while pointing downward with one’s right arm.

Dieudonne has been convicted seven times for inciting hatred of Jews. On Thursday, a French court banned him from performing in Nantes in what was to be the debut of his new show, “The Wall.”

On the website of the far-right JDL, the hackers posted a caricature of the league’s logo, featuring the silhouette of a ballet dancer framed by the Star of David of the original logo.

“Dear Zionist enemies, some of you (all?) interpret the quenelle to a be secretly anti-Semitic. This is a mistake,” the text posted on the JDL’s website read. “I realize you don’t like Dieudonne but unfortunately, you don’t understand the material. This can be fixed.”

The hackers also posted videos claiming the quenelle is an anti-establishment expression.

On Monday, Le Monde reported that French police are looking to question a man who posted a photo of himself performing the quenelle in front of a synagogue in Bordeaux, one of dozens of such photos that have surfaced in French media in recent weeks.