The Russian-led effort to spread misinformation and sow discord ahead of the 2016 U.S. election also used the social network Instagram, parent company Facebook acknowledged in Congress Wednesday.
Facebook general counsel Colin Stretch told a hearing that Instagram posts by suspect Russian accounts were seen by some 20 million Americans last year.
"We now discovered, in the last 48 hours, 120,000 Russian-based posts on Instagram," Stretch told the Senate Intelligence Committee hearing.
The latest data on Instagram is on top of the estimated 126 million Americans exposed to Facebook posts from Russian entities seeking to create divisions during the election campaign.
"So all told, that gets you to approximately -- a little less than 150 million," Stretch said in response to questioning from Democratic Senator Mark Warner.
The hearing was the second in Congress this week in which social media and internet firms including Google and Twitter have been called to explain how fake news and other disinformation was allowed to spread during the election campaign.
Many of the social media posts came from the Internet Research Agency, which has been linked to Russian intelligence efforts to disrupt the US election.
Twitter told lawmakers on Tuesday it found that nearly 37,000 automated "bot" accounts with Russian links generated 1.4 million tweets that were seen by a potential 288 million people in the three months before the November presidential election.
Warner, who has become one of the most vocal critics of the internet firms, repeated his claim that "Russian operatives are attempting to infiltrate and manipulate American social media to hijack the national conversation and to make Americans angry, to set us against ourselves and, at their most basic, to undermine our democracy."