Facebook removed Trump campaign ads on Thursday that targeted the far-left Antifa movement, including one with an downward-pointing red triangle that apparently resembled a Nazi designation symbol for political prisoners in concentration camps.

Facebook removed the ads after the Anti-Defamation League pointed out this out, reported The Washington Post.

A red inverted triangle was used by the Nazis to identify political enemies, including, but not limited to, Communists, liberals, Social Democrats and Freemasons. Jews were designated with a yellow Star of David, some of which had the comparable word for “Jew” in between the star in the language of the occupying country.

“Our policy prohibits using a banned hate group’s symbol to identify political prisoners without the context that condemns or discusses the symbol,” a Facebook spokesperson said to reporters.

Trump campaign spokesperson Tim Murtaugh told news outlets that the inverted red triangle symbol has been used by Antifa, and the insignia is branded on products sold online, such as water bottles and iPhone cases.

“We would note that Facebook still has an inverted red triangle emoji in use, which looks exactly the same, so it’s curious that they would target only this ad,” said Murtaugh.

In a statement, ADL national director and CEO Jonathan Greenblatt said, “We have long seen how Facebook has allowed some of the worst elements of society into our homes and our lives. When this hate spreads online,face it causes tremendous harm and also becomes permissible offline.”