Twitter on Friday said the number of Russia-linked accounts firing off tweets evidently aimed at the US election in 2016 was more widespread than initially determined.
The social media company found, and shuttered, an additional 1,062 accounts associated with the Internet Research Agency, considered a "troll farm" connected to the Russian government, Twitter said in an update posted online.
Along with Google and Facebook, Twitter has been criticized for allowing the spread of bogus news -- some of which was directed by Russia -- ahead of the 2016 US election and in other countries.
Twitter also said it is emailing notifications to almost 670,000 people in the US who followed, retweeted, or "liked" posts from any of those suspect accounts during the election period.
"Any such activity represents a challenge to democratic societies everywhere, and we're committed to continuing to work on this important issue," Twitter said in the update.
For the 10-week time span investigated prior to the November, 2016 election, Twitter identified a total of 3,814 Internet Research Agency-linked accounts, according to the San Francisco-based company.
Those accounts posted 175,993 tweets, approximately 8.4 percent of which were election related, Twitter said.
The analysis at Twitter also found an additional 13,512 automated accounts identified as "Russia-linked" and tweeting election-related content during that period, bringing the total to 50,258 accounts.
Twitter said it is sharing information about the accounts with Congress, where testimony late last year by Twitter, Facebook and Google revealed startling new data showing many more millions of Americans were exposed to the fake news than previously thought.
The companies said they were taking necessary steps to rid their platforms of disinformation, propaganda and provocation.
US legislators have been investigating whether President Donald Trump's campaign colluded with Russia in its bid to influence the 2016 US elections.