On Wednesday, Facebook said that it had discovered evidence of ad spending related to fake accounts “likely operated out of Russia” during the 2016 US presidential election.

SAN FRANCISCO — Facebook says an internal investigation has uncovered $100,000 in advertising spending by hundreds of fake accounts and pages, likely operated out of Russia, which 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. A small number of the ads named then Republican nominee Donald Trump and his Democratic challenger Hillary Clinton.

The ads were traced to a Russian “troll farm,” a Facebook official said on the condition of anonymity because he is not authorized to speak publicly on the matter.

Facebook says it has shared the 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.” In a white paper earlier this year, the Silicon Valley company outlined how this strategy can be used to misinform the public, including the creation of networks of fake accounts to distort public sentiment.

Facebook uncovered 470 suspicious and likely fake Facebook accounts and pages that it believes operated out of Russia. The ads targeted specific populations and geographies. The official declined to share any of the ads, citing the company’s data privacy policy.

The accounts and the pages in question have been deleted. In hunting for other suspect ads, Facebook turned up $50,000 spent on 2,200 ads it says could have been politically related.

The internal investigation into politically motivated ads began this spring after discussions with U.S. officials, the Facebook official said.

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

Mueller was named to the post after Trump fired former FBI…