Twitter on Thursday banned advertisements from accounts owned by Russian media outlets Russia Today (RT) and Sputnik, citing allegations by U.S. intelligence agencies that the outlets tried to interfere with the 2016 U.S. election.

Election-meddling is “not something we want on Twitter,” the San Francisco-based social network said in an unsigned statement.

“We did not come to this decision lightly, and are taking this step now as part of our ongoing commitment to help protect the integrity of the user experience on Twitter,” the company said.

In addition to Twitter, Facebook (FB) and Alphabet’s Google (GOOGL) have recently detected that suspected Russian operatives used their platforms last year to purchase ads and post content that was politically divisive.

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RT said in a statement on its website that it has never been involved in any illegal activity online and “never pursued an agenda of influencing the U.S. election through any platforms, including Twitter.”

A representative for Sputnik was not immediately available for comment.

Twitter (TWTR) said last month it had suspended about 200 Russian-linked accounts as it investigates propaganda efforts related to last year’s U.S. presidential race.