Washington D.C. (CNN) Facebook says it removed more than 100 accounts this week from the main service as well as its subsidiary Instagram over concerns they may be connected to the Russia-based Internet Research Agency (IRA) -- the same troll operation targeted by special counsel Robert Mueller in his sprawling Russia investigation.

The social media giant acknowledged Tuesday that it removed the pages following a tip from the FBI.

"We blocked over 100 Facebook and Instagram accounts due to concerns that they were linked to the Russia-based Internet Research Agency (IRA) and engaged in coordinated inauthentic behavior, which is banned from our services," says Nathaniel Gleicher, Facebook's head of cyber security policy, on Tuesday.

The company did not disclose details of the pages it removed.

Earlier on Tuesday, a website claiming to be run by the IRA took responsibility for a network of fake social media accounts, many targeting American voters -- an operation similar to what the group orchestrated in the run-up to the 2016 presidential elections.

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