Facebook said Tuesday it shut down more than 2,600 fake accounts linked to Iran, Russia, Macedonia and Kosovo and aiming to influence political sentiment in various parts of the world.
It was the latest effort by the leading social network to shut down "inauthentic" accounts on Facebook and Instagram seeking to influence politics in the U.S. and elsewhere.
Facebook said the accounts blocked in the four countries were not necessarily centrally coordinated but "used similar tactics by creating networks of accounts to mislead others about who they were and what they were doing," said Nathaniel Gleicher, head of cybersecurity policy for the company.
"We are constantly working to detect and stop this type of activity because we don't want our services to be used to manipulate people," Gleicher said in a blog post.
"In each case, the people behind this activity coordinated with one another and used fake accounts to misrepresent themselves, and that was the basis for our action."
Gleicher said Facebook — which has made similar moves in recent months — was making progress in rooting out fake accounts but noted that "it's an ongoing challenge because the people responsible are determined and well-funded. We constantly have to improve to stay ahead."
Links to Iran
In the latest action, Facebook said it removed 513 pages, groups and accounts tied to Iran and operating in Egypt, India, Indonesia, Israel, Italy, Kashmir, Kazakhstan and various areas of the Middle East and North Africa.
Similar to other manipulation campaigns, the users posed as locals and "made-up media entities" and posted news stories about topics including sanctions against Iran, tensions between India and Pakistan, issues in the Middle East and the crisis in Venezuela.
"Although the people behind this activity attempted to conceal their identities, our review linked these accounts to Iran," Gleicher said.
Links to Russia, Macedonia and Kosovo
Another 1,907 accounts linked to Russia were also blocked. These sought to influence sentiment related to Ukrainian news and politics, the situation in Crimea and corruption.
Facebook said 212 Facebook accounts originating in Macedonia and Kosovo were shut down for misrepresenting themselves as users in Australia, the United States and Britain and sharing content about politics, astrology, celebrities and beauty tips.
Earlier this month, Facebook said it blocked online manipulation efforts in Britain and Romania from users seeking to spread hate speech and divisive comments.
In January, Facebook took down hundreds of accounts from Iran that were part of a vast manipulation campaign operating in more than 20 countries.