The company said that it had identified ads that were designed to provoke reactions over divisive political issues, including race, gay rights, gun control, and immigration.
Alex Stamos, Facebook chief security officer, posted a blog on the social network acknowleding it had found "approximately $100,000 in ad spending from June of 2015 to May of 2017 — associated with roughly 3,000 ads — that was connected to about 470 inauthentic accounts and pages in violation of our policies."
Stamos added that analysis suggested that the 470 accounts and pages were "affiliated with one another and likely operated out of Russia." It has since shut down those accounts and pages that were still active.
According to various reports, Facebook officials have also told U.S. congressional authorities that fake accounts posting the ads were created by a Russian company called the Internet Research Agency, a Kremlin-linked propaganda group that is infamous for trolling across social and other media sites.
Most of the 3,000 ads did not refer directly to last year's presidential candidates, Donald Trump or former Secretary of State Hillary Clinton.
The revelation adds to mounting evidence of Russian interference in the 2016 presidential election. American intelligence agencies including the FBI are certain of a Russian influence campaign specifically designed to denigrate Clinton and bolster Trump.
Facebook staff briefed Senate and House intelligence committees investigating Russian tampering of the U.S. election this week.
Stamos confirmed in his blog post that Facebook had shared its findings with U.S. authorities and "will continue to work with them as necessary."
"Our analysis suggests these accounts and pages were affiliated with one another and probably operated out of Russia," Stamos added. Most of the ads were aimed at "‘amplifying divisive social and political messages across the ideological spectrum."
The Internet Research Agency has been involved in previous hoaxes. In 2014, it used fake accounts to post fake news items about a chemical spill in Louisiana.
Facebook has been accused of not doing enough to clamp down on fake news. Two-thirds of U.S. adults said they got their news from Facebook last year.
This story first appeared on campaignlive.co.uk.