Twitter on Friday said it suspended more than 50 white nationalist accounts for violating policies against violent extremism.

"The accounts in question were suspended for violating our policies in relation to violent extremism," a Twitter spokesman told AFP, confirming a report by NBC News.

The move came days after release of a report by nonprofit Global Project Against Hate and Extremism saying that propaganda pushed by white supremacist network Generation Identity is "rampant" on Twitter and YouTube.

"At this point, it is well accepted that white supremacy is as significant a threat for generating mass casualty terrorist acts internationally as other forms of extremism," the report concluded.

"Yet, there is a double standard when it comes to how online platforms treat content produced by white supremacists compared to content by Islamic extremist groups like ISIS or Al-Qaeda."

Research by the GPAHE found 67 Twitter accounts for Generation Identity chapters in 14 countries with nearly 140,000 followers.

That tally did not include accounts of individual "Identarians," such as unofficial leader Martin Sellner who heads an Austrian chapter, according to the nonprofit organization.

On YouTube, GPAHE found at least 12 countries represented by 31 GI chapters with about 86,000 subscribers, the report indicated.

The nonprofit contended that Generation Identity propaganda has "inspired" a half-dozen mass attacks since late 2018, including the mosque attacks in Christchurch, New Zealand.

Propaganda includes contending white people are being replaced in their home countries by immigrants, according to the report.

"It would be inconceivable for social media platforms to allow ISIS propaganda to spread and grow unchecked, but that is exactly what is happening with Identitarianism - the ideology that underpins Generation Identity," the report said.

Twitter suspended the accounts for violating its policy against terrorist organizations or violent extremists who affiliate with or promote their "illicit activities," according to the San Francisco-based firm.