Twitter told Congressional investigators on Thursday that it had found about 200 accounts that the company believes are linked to the Russian operatives who purchased ads on Facebook in an attempt to influence the 2016 election.

“Of the roughly 450 accounts that Facebook recently shared as a part of their review, we concluded that 22 had corresponding accounts on Twitter,” the company said in a blog post. In addition, Twitter noted that it had found 179 other “related or linked accounts” and “took action” on those that violated the Twitter rules.

“Over the coming weeks and months, we’ll be rolling out several changes to the actions we take when we detect spammy or suspicious activity, including introducing new and escalating enforcements for suspicious logins, Tweets, and engagements,” the blog post said, without offering further details. “These are not meant to be definitive solutions.”

Across the board, Twitter said it is seeing more malicious activity on the platform all the time. The company catches over “3.2 million suspicious accounts globally per week,” which is more than double the amount that it caught last year.

Twitter additionally said that it handed over to Congress all promoted tweets belonging to the Russian government-backed news outlet Russia Today, and that it plans to work with the Federal Election Commission to “review and strengthen guidelines” for digital political ads.

During the 2016 campaign, Twitter said it eliminated “thousands” of fake accounts tweeting “text to vote” for Hillary Clinton messages, a form of voter suppression through misinformation.

In its most recent quarterly financial report, Twitter disclosed that it has about 328 million users worldwide and about 68 million in the U.S., meaning that the suspicious Russian accounts — bots or otherwise — make up a fraction of a fraction of the social network’s users. But bots, beyond those of Russian extraction, were able to influence the conversation online effectively during the 2016 election, researchers at Oxford University concluded earlier this year.

“Bots infiltrated the core of the political discussion over Twitter, where they were capable of disseminating propaganda at mass-scale,” said study authors Samuel Woolley and Douglas Guibeault.

Twitter, as well as Google and Facebook, have long been reluctant to publicly disclose any possible attempts by foreign actors to use their platforms to influence democratic elections. Facebook only shared evidence that Russian troll farms paid $100,000 to promote ads for that purpose with Congress in early September, and investigators remain skeptical that that’s the whole story — or that these Silicon Valley companies were powerless to stop such an intrusion.

Facebook, Google, and Twitter will have two chances apiece to explain themselves in Washington: the Senate Intelligence Committee is reportedly planning a November 1 public hearing for the three companies to testify, and its counterpart in the House is aiming for the same thing sometime in October. Given that Sen. Mark Warner, the ranking Democrat on the Senate Intel Committee, called Twitter’s Thursday testimony “pretty disappointing” — these hearings will likely be painful for the companies present.