(Adds expert analyst comments, background on tweets)
By Christopher Bing and Jack Stubbs
Oct 17 (Reuters) - Twitter published a trove of some 10 million tweets that it said were linked to state-backed operations by Russia and Iran, shedding new light on the scale of misinformation campaigns mounted by the two nations, apparently designed to influence voters and sow dissension in the United States and elsewhere.
The social media service, which has more than 300 million monthly users worldwide, said it had identified 3,841 accounts affiliated with the St. Petersburg-based Internet Research Agency, or IRA, a Russian “troll farm” that has been indicted by U.S. Special Counsel Robert Mueller for attempts to interfere with the 2016 U.S. presidential election. It found another 770 Twitter accounts that it traced back to Iran.
"We are making this data available with the goal of encouraging open research and investigation of these behaviors from researchers and academics around the world," Twitter said in a statement on its "elections integrity" site.
In total, the exposed accounts shared more than 10 million tweets and 2 million images and videos, Twitter said, before being taken down.
Twitter had already made public the existence of tweets it believes to be the product of foreign misinformation campaigns, but the release of the tweets themselves on Wednesday will allow researchers to learn much more about Russia and Iran’s disinformation efforts on Twitter since 2016.
"There has been a lot of misunderstanding on the IRA operation, notably because the public was working with bits and pieces of data," said Camille Francois, director of research for social media data analytics firm Graphika. "Comprehensive datasets like these allow for a fuller understanding of the scope and nature of these operations."
Russia and Iran have both denied accusations that they attempted to influence U.S. voters on social media or through other means.
Twitter's publication of the tweets comes just weeks before U.S. Congressional elections which are already the subject of Russian and other foreign-directed social media campaigns, according to senior U.S. intelligence officials.
"The Russian operation was much more skilled," said Ben Nimmo, a senior fellow at the Atlantic Council’s Digital Forensic Research Lab, which published a detailed analysis of the tweets on Wednesday. "It masqueraded as real Americans to turn real Americans against Hillary Clinton, and against each other,” he added, referring to Donald Trump's presidential election challenger.
The Iranian operation was more clumsy, attempting to use social media to draw people towards pro-regime messaging sites, according to Nimmo.
The tweets made public by Twitter either insult or praise certain election candidates, activists and other influential targets or topics with charged rhetoric.
For example, the Digital Forensic Research Lab identified what it described as a Russian-linked 2017 Twitter campaign aimed at influencing the debate over U.S. National Football League players kneeling during the national anthem to protest police violence against African-Americans.
While the automated accounts stoked anger on one side with messages such as "Rosa Parks took a seat. We must #TakeTheKnee," they also retweeted posts directly attacking NFL players for their part in the protests.
"The IRA and the Iranian operation covered in Twitter's data today are only the tip of the iceberg for foreign manipulation of social media," said Francois. (Reporting by Chris Bing in Washington and Jack Stubbs in Bratislavia, Slovakia Writing by Jim Finkle and Patrick Graham)