Twitter has banned Russian media companies Russia Today (RT) and Sputnik from advertising on its service after it found that both had “attempted to interfere with the [2016 U.S.] election on behalf of the Russian government” using the social network.

“This decision was based on the retrospective work we’ve been doing around the 2016 U.S. election and the U.S. intelligence community’s conclusion that both RT and Sputnik attempted to interfere with the election on behalf of the Russian government,” the company said.

Twitter confirmed that the two media firms are the only ones that it found to have tried to interfere with the election. While it has banned both outlets from running ads, it will allow them to retain their accounts on the service “in accordance with the Twitter Rules.”

It added that it will donate the revenue it has received from RT advertising efforts — which it puts at $1.9 million to date — to fund research into the use of its service in civic engagement and elections. The company promised to share more details on that soon.

Off-boarding advertising from all accounts owned by Russia Today (RT) and Sputnik. We’re donating all projected earnings ($1.9mm) to support external research into the use of Twitter in elections, including use of malicious automation and misinformation. https://t.co/zIxfqqXCZr — jack (@jack) October 26, 2017

To add fuel to the fire, RT’s head of social media earlier suggested Twitter had encouraged the media outlet to run advertising around the election.

The microblogging platform has been swept into the issue of how the internet was used to influence the 2016 election, which started out with major questions asked of Facebook after a Director of National Intelligence report in January found evidence of a campaign led out of Russia.

Twitter provided information to Congress last month and, following a bipartisan Congressional bill proposing new regulations for online ads, it pledged to be more transparent over political ads and electioneering with a new system. Not only will political ads on the service be labeled accordingly, but Twitter has created a transparency center that details political ads running on Twitter, the content/creatives behind them, how long they have run and who they are targeted at.