International Business Machines Corp. suspended its advertising on X, the social media platform formerly called Twitter, after the technology company’s ads were found by a watchdog group near pro-Nazi posts.

Media Matters released a report Thursday showing ads for IBM, Apple Inc., Oracle Corp., Comcast Corp.’s Xfinity brand and the Bravo television network, which is owned by Comcast’s NBCUniversal, running on the social network next to pro-Nazi posts.

“IBM has zero tolerance for hate speech and discrimination and we have immediately suspended all advertising on X while we investigate this entirely unacceptable situation,” a company spokesperson said in an email, noting that it was responding to the situation reported by Media Matters.

Comcast is looking into the matter, a spokesperson said. Apple and Oracle didn’t immediately respond to requests for comment. IBM’s decision was reported earlier by the Financial Times.

Elon Musk, the billionaire owner of X, on Wednesday endorsed an antisemitic post on the service. Responding to an X user on Wednesday who said that it’s unfair to make generalizations about Jewish communities promoting hatred toward white people, Musk wrote that the person was “right that this does not extend to all Jewish communities, but it is also not just limited to ADL.”

--With assistance from Todd Shields and Mark Gurman.

(Updates with comments from Comcast spokesperson in the fourth paragraph.)