SAN FRANCISCO — Facebook says an internal investigation has found $100,000 in advertising spending by hundreds of fake accounts and pages likely operated out of Russia that sought to sow political division during the U.S. presidential election.

The giant social network says the ads that ran between June 2015 and May 2017 carried "divisive social and political messages across the ideological spectrum," touching on topics such as LGBT, race, immigration and gun rights, though most of them did not directly mention the election.

Facebook says it has shared these findings with U.S. investigators.

The ads are part of a new kind of attack that Facebook calls "information operations," a web of nefarious and insidious activities that extends far beyond "fake news." The Silicon Valley company outlined how this strategy can be used to misinform the public earlier this year in a white paper including the creation of networks of fake accounts to distort public sentiment.

Facebook says it has deleted the accounts and the pages in question. It also hunted for other suspect ads and found $50,000 spent on 2,200 ads it says could have been politically related.

Special counsel Robert Mueller and congressional committees are investigating whether Russia meddled in the election and if that meddling had any connection to President Trump’s administration.

Mueller was named to the post after Trump fired former FBI director James Comey, who had been leading the investigation. President Vladimir Putin and other Russian officials have denied meddling in the U.S. election.