Twitter owner Elon Musk hit back at the Anti-Defamation League (ADL) on Tuesday, after its chief executive said comments made by the US billionaire about philanthropist George Soros "will embolden extremists".
Jonathan Greenblatt went on to write that far-right Twitter users "contrive anti-Jewish conspiracies and have tried to attack Soros and Jewish communities as a result" of Mr Musk's remarks.
Mr Musk later tweeted that "ADL should just drop the 'A'," making it simply "the Defamation League".
The spat came as Israel's Foreign Ministry accused Mr Musk of fuelling anti-Semitic rhetoric. A tweet from its official account read: "The phrase ‘The Jews’ spiked today on the list of topics trending on Twitter following a tweet with anti-Semitic overtones by none other than the owner and CEO of the social network, Elon Musk.”
Mr Musk's original tweet said "Soros reminds me of Magneto", the latter being a villain in Marvel comic books.
Mr Soros is a Holocaust survivor and Magneto is also cast as one.
The Hungarian-American billionaire and philanthropist has been the subject of many anti-Semitic conspiracy theories in the past, which the ADL says stem from his "funding of liberal causes" and include claims he "masterminds specific global plots or manipulates particular events to further his goals", according to an article on its website.
The row between Mr Musk and the ADL marks a change from Mr Greenblatt's previous views of the billionaire. In October, he described Mr Musk as an "extraordinary innovator".
It comes shortly after US President Joe Biden told a White House reception, marking Jewish-American Heritage Month, that Jewish-Americans were "shattered by a long and painful history of the oldest, the most sinister forces of hate and anti-Semitism”.