Twitter apologized, Friday, after allowing “Kill All Jews” to becoming a top trending topic on the social network.

“Kill All Jews” became a top trending topic on Twitter, Thursday, after the phrase was graffitied by a vandal onto a Brooklyn synagogue.

BREAKING: The New York City Police Department releases a photo of the man they suspect of writing anti-Semitic statements in a Brooklyn synagogue NYPD says the messages included “Die Jew Rats We Are Here,” “Jews Better Be Ready,” "Rose" and “Hitler”https://t.co/oEUQ3GYDXj pic.twitter.com/n6NJYQstfg — Ryan Saavedra (@RealSaavedra) November 2, 2018

“This phrase should not have appeared in trends, and we’re sorry for this mistake,” claimed a Twitter spokesman to the Wrap. “At times, we do prevent certain content from trending and we have now done so with this trend. This was trending as a result of coverage and horrified reactions to the vandalism against a synagogue in New York. Regardless, it should not have appeared as a trend.”

On Twitter’s help page, the company explains that sometimes it “may prevent certain content from trending,” including trends which, “Contain profanity or adult/graphic references,” “Incite hate on the basis of race, ethnicity, national origin, sexual orientation, gender, gender identity, religious affiliation, age, disability, or disease,” and, “Violate the Twitter Rules.”

Twitter has faced repeated criticism for refusing to take action against anti-Semitism on its platform, most notably from Nation of Islam leader Louis Farrakhan — despite the fact that Twitter frequently suspends popular conservative and libertarian accounts.

Just weeks before the fatal Tree of Life Synagogue shooting in Pittsburgh last month, Twitter refused to take action against a post from Farrakhan which compared Jews to “termites.”

“Just in from a @Twitter spokesperson: Louis Farrakhan’s tweet comparing Jews to termites is not in violation of the company’s policies. The policy on dehumanizing language has not yet been implemented,” declared Buzzfeed News’ Joe Bernstein on Twitter in October. “So if you want to compare Jews to rats/insects — get it in while you can!”

Twitter has also previously refused to remove a post from Farrakhan attacking “the Satanic Jew and the Synagogue of Satan,” and a post from a Brit which called Jews, “Absolutely vile.”