More than 6.6 million tweets circulated across Twitter (TWTR) in the month leading up to the 2016 election that were tied to “fake news and conspiracy news publishers,” the Knight Foundation revealed on Thursday. The study, which was commissioned by the Knight Foundation and produced by The George Washington University, also found that 4 million tweets that linked to those “fake news and conspiracy” publishers were found on Twitter between mid-March 2017 to mid-April 2017.

“More than 80% of accounts that repeatedly spread misinformation during the 2016 election campaign are still active,” the Knight Foundation continued, “and they continue to publish more than a million tweets on a typical day.”

Twitter and Facebook have come under fire in the last two years over allegations that the Russians used social media to meddle in the U.S. election. Those tactics included creating a slew of fake accounts and linking them to conspiracy sites and fake news publishers to sway public opinion.

According to the Knight Foundation, its findings show activity by the Russians on Twitter to spread misinformation. The service added that the majority of the accounts were “pro-Republican” and “pro-Trump.” Some of the accounts, however, did support liberal causes.

In a statement to Fortune responding to the study, Twitter’s global vice president of trust and safety Del Harvey said Twitter works quickly to remove harmful content.

“Firstly, this study was built using our public API and therefore does not take into account any of the actions we take to remove automated or spammy content and accounts from being viewed by people on Twitter. We do this proactively and at scale, every single day,” Harvey said. “Secondly, as a uniquely open service, Twitter is a vital source of real-time antidote to day-to-day falsehoods. We are proud of this use case and work diligently to ensure we are showing people context and a diverse range of perspectives as they engage in civic debate and conversations on our service.”

Harvey’s statement—and the result of the study—come just days after Twitter published a blog post updating users on its “elections integrity work.” Harvey noted in the blog post that Twitter has updated its rules to better control fake accounts and hacked content shared through the site. The company said that it’s also been working on removing misleading, politically motivated accounts.

“We continue to partner closely with the RNC, DNC, and state election institutions to improve how we handle these issues,” Harvey wrote in the blog post.