As many as 126 million Americans were exposed to Russia-backed content uploaded to Facebook around the 2016 US presidential election, the social network revealed on Tuesday.
In total around 80,000 posts were uploaded to the site by Russian operatives, with most of the content focusing on wedge issues in American culture, Reuters reported.
The figures were revealed by Facebook ahead of the company’s appearance at a Senate Judiciary Committee hearing where it will assess Moscow's manipulation of the network to influence the vote. Twitter and Google are also scheduled to appear.
The content, published between June 2015 and August 2017, was posted from a Russian internet research agency with ties to the Kremlin, according to The Washington Post. Facebook has since removed the posts and reported the accounts to US officials.
Facebook's general counsel Colin Stretch said: "These actions run counter to Facebook's mission of building community and everything we stand for.”
"And we are determined to do everything we can to address this new threat."
The Judiciary Committee is probing Russia’s disinformation campaign targeting the 2016 vote. Russia has denied all wrongdoing.
Twitter revealed on Tuesday some 2,752 accounts were linked to the same research agency, far more than the company initially admitted. The accounts, which have since been suspended, put out 1.4 million election-related tweets between September and November 15 last year, half of them automated.
Twitter also fund nine Russian accounts that bought ads on the site, mostly from state-back outlet RT. The company said last week it would no longer accept ads from RT, or the similarly state-backed outlet Sputnik.
Google said it found $4,700 (£3,600) in advertising linked to Russian-backed accounts, along with 18 YouTube channels used for disinformation. The channels hosted 1,108 videos, however they only amounted to 309,000 US views between June 2015 and November 2016.