Ads for more than three dozen brands including major corporations appeared on the Twitter pages of white nationalist accounts in recent days after Twitter owner Elon Musk restored hordes of banned users to the social media platform.

Promoted tweets from Amazon, Snap, Uber and the U.S. Department of Health and Human Services, among others, appeared inadvertently on the pages of at least two white nationalists, Andrew Anglin and Patrick Casey, both of whom said their accounts had been banned but were restored recently after Musk took control of Twitter in late October.

In a vast cost-cutting campaign, Musk fired hundreds of Twitter employees, including entire teams devoted to content moderation of the site, including ensuring ads not appear on content brands would find objectionable.

More than a third of Twitter’s top 100 marketers have not advertised on the social media network in the past two weeks, a Washington Post analysis of marketing data found — an indication of the extent of skittishness among advertisers about billionaire Elon Musk’s control of the company.

Dozens of top Twitter advertisers, including 14 of the top 50, have stopped advertising in the few weeks since Musk’s chaotic acquisition of the social media company, according to The Post’s analysis of data from Pathmatics, which offers brand analysis on digital marketing trends.

A coterie of large advertisers and marketing agencies have said they will slow down or pause spending on the site out of concern that Musk laying off half the company’s workforce will hurt its ability to police hate speech and sexually explicit content, which they do not want their ads showing up next to.

More than 50 organizations, however, signed a letter to Twitter’s top advertisers this week asking them to cease spending on the social media site if Musk “follows through on his plans to undermine brand safety and community standards including gutting content moderation.”

The groups noted that they were concerned about the spike in hate and disinformation on the platform in the hours after Musk took ownership.

“Not only are extremists celebrating Musk’s takeover of Twitter, they are seeing it as a new opportunity to post the most abusive, harassing, and racist language and imagery,” the groups wrote.

Many of the civil rights groups that met with Musk on Tuesday were part of the Stop Hate for Profit coalition that orchestrated an advertiser boycott of Facebook two years ago. Hundreds of companies paused their advertising on Facebook to protest hate speech on the social media site.