YouTube said last week it was further cracking down on content on the platform and removing videos " alleging that a group is superior in order to justify discrimination, segregation or exclusion."

However, accounts featuring white supremacists, white nationalists, and alt-right leaders, including former KKK leader David Duke, were still found on YouTube on Wednesday, CNN reports.

YouTube says that "enforcement will take time," and that its policies indicate a channel has to get three strikes (videos removed) within a 90-day period in order to be removed.

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A week after YouTube said it was cracking down on videos glorifying Nazi ideologies and other extremist beliefs, channels showing prominent white supremacists and white nationalists were still up on the video-sharing platform.

CNN reported Tuesday night that accounts belonging to two of the most notable alt-right figures — former KKK leader David Duke and white nationalist Richard Spencer — were up on YouTube. These two channels include videos warning about the "war on whites," and rails against the "Ziomedia" (CNN notes that's a term for Jewish reporters).

It appears Spencer's channel has since been removed from YouTube. While Duke's channel remains up, some videos on Duke's channel have had comments and suggested videos disabled, and feature warnings about "content that may be inappropriate or offensive to some audiences."

However, other problematic channels are still up on YouTube with thousands of followers and no content warnings. This includes accounts run by Jared Taylor's American Renaissance, conspiracy theorist Jeff Rense, neo-Nazi Mark Collett, and the Red Elephants' Vincent James.

Read more: YouTube will remove thousands of videos supporting white supremacy, Nazis and conspiracy theories that deny the existence of mass shootings and other violent events

YouTube declined to comment directly on CNN's report about Duke's and Spencer's accounts. The website's new policy, enacted June 5, bans "videos alleging that a group is superior in order to justify discrimination, segregation or exclusion based on qualities like age, gender, race, caste, religion, sexual orientation or veteran status." YouTube said that its new policy applies to videos promoting and glorifying Nazi ideology, and denying the existence of "well-documented violent events" like the Holocaust.

On Wednesday, YouTube told Business Insider that enforcing its new policy "will take time," and that its past enforcement of policies in the past "has always worked." Under its policy, a channel is issued a strike when a video is removed in violation of YouTube guidelines. Channels will be terminated if they get three strikes within a 90-day period, or if they "egregiously" violate policies.