Both Twitter and Facebook told  Congress this week that the extent of Russian election meddling using their platforms was far greater than previously known.

Twitter told Congress that Russia-linked accounts “generated approximately 1.4 million automated, election-related tweets, which collectively received approximately 288 million impressions,” between a period of September 1 and November 15 of last year.

“For our analysis, we studied the time period of September 1 – November 15, 2016 covering 16 billion unique Tweets, (i.e., excluding retweets),” said a source familiar with the testimony. Twitter’s acting general counsel, Sean Edgett, wrote that the company has “identified 36,746 accounts that generated automated, election-related content and had at least one of the characteristics we used to associate an account with Russia.”

These new figures are much higher then the original 200 identified accounts Twitter had reported to the Senate Intelligence Committee just last month. Which at the time, prompted Democratic Sen. Mark Warner to call the findings “deeply inadequate.”

Facebook disclosed similar findings to Congress, reporting that between 2015-2017 Russia-linked accounts generated approximately 80,000 posts that were seen by roughly 126 million users.

“We estimate that roughly 29 million people were served content in their News Feeds directly from the IRA’s 80,000 posts over the two years,” wrote Facebook’s counsel Colin Stretch.

The IRA (Internet Research Agency) is a known Russian “troll factory” responsible for spreading disinformation and propaganda on social media throughout the 2016 U.S. election. It is estimated that the IRA spent just $46,000 on pre-election day advertisements, or just 0.05% of the $81 million spent by both the Trump and Clinton campaigns combined.

Twitter in its testimony wrote that it had uncovered more accounts used by the IRA. “We connected the 201 accounts we initially identified with Congressional investigators to broader Russian election-focused activity on Twitter, including the full set of 2,752 accounts that we now believe are associated with the IRA,” the testimony says.

Twitter said it will cooperate fully with the Senate Intelligence Committee disclosing any future accounts found to be in violation of its rules to investigators. It has also taken proactive measures to discourage future attempts for using its site as a propaganda tool by the Russians instituting new ad-policy as well as banning RT and Sputnik, two Russian state-owned news agencies which participated in the spread of false information during the campaign.