Russian President Vladimir Putin addressing the news media in Sochi, Russia. Thomson Reuters

Twitter and Facebook will tell Congress this week that Russia's US election meddling on their platforms was wider than originally reported.

Twitter will say more than 30,000 Russia-linked accounts generated 1.4 million tweets during the final stretch of the campaign.

Facebook will say nearly 126 million people were exposed to content tied to Russia-linked accounts over a two-year period.

Twitter will tell Congress this week that Russia-linked accounts "generated approximately 1.4 million automated, election-related tweets, which collectively received approximately 288 million impressions" last year from September 1 to November 15.

"For our analysis, we studied the time period of September 1 - November 15, 2016 covering 16 billion unique Tweets, (i.e., excluding retweets)," a source familiar with Twitter's testimony said. "Our review was deliberately broad, capturing 189 million election-related Tweets."

In a portion of the prepared testimony, which Business Insider obtained Monday, Twitter's acting general counsel, Sean Edgett, wrote that the company "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."

That is far higher than the number of Russia-linked accounts Twitter initially disclosed to the Senate Intelligence Committee in a closed-door interview last month. Twitter representatives reportedly told investigators that it had uncovered only 201 Russia-linked accounts, leading Democratic Sen. Mark Warner to tell reporters that the interview was "deeply inadequate."

When Edgett appears before the Senate intelligence and judiciary committees this week, however, he will testify that those 36,746 accounts "generated approximately 1.4 million automated, election-related Tweets, which collectively received approximately 288 million impressions."

Twitter emphasized in its prepared remarks that the nearly 37,000 accounts represented "1/100th of a percent (0.012%) of the total accounts on Twitter at the time."

By comparison, Facebook will tell Congress that Russia-linked accounts produced approximately 80,000 posts on the platform from 2015 to 2017 that were seen by about 126 million Americans.

"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," Facebook's counsel Colin Stretch wrote in the testimony obtained by Business Insider. He added that Facebook estimated that "approximately 126 million people may have been served one of their stories at some point during the two-year period."

The IRA, or Internet Research Agency, is a Russian "troll factory" that mass-produced disinformation and propaganda on social media leading up to the US election.

Twitter wrote in its testimony that it uncovered "more accounts linked to the Internet Research Agency ("IRA") as a result of our review."

"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.

Roughly 9% of the tweets from the 2,752 IRA-linked accounts were election-related, Twitter said, and more than 47% of those tweets were automated.

The company said that all 2,752 accounts had been suspended and that the company was "proactively giving committee investigators the handles of these accounts, and we have taken steps to block future registrations related to these accounts-- and we have pledged to Congress that we will inform them as we uncover more related accounts."

Twitter banned the Russian news agencies RT and Sputnik from advertising on its platform last week. The company said in its prepared remarks that it had "identified nine accounts that both had at least one criteria for Russian origin and promoted election-related content that violated existing or recently implemented ads policies. Two of those accounts were @RT_COM and @RT_America."

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