Facebook officials on Wednesday told congressional investigators that the company discovered it sold $100,000 worth of ads, many about contentious political issues, to a Russian company during the 2016 election, the Washington Post reported.

The Washington Post reported, citing several unnamed sources familiar with Facebook’s findings, that the company traced the sales to a Russian firm. The ads began in summer 2015, according to the report, and a small portion named Donald Trump, then the Republican nominee, and Democratic nominee Hillary Clinton.

An unnamed Facebook official told the Washington Post that there was “evidence that some of the accounts” that promoted those ads “are linked to a troll farm in St. Petersburg, referred to as the Internet Research Agency, though we have no way to independently confirm.”

Per the report, the official said that Facebook is limited by its “data policy and federal law” and “won’t be releasing any ads,” but said they “were directed at people on Facebook who had expressed interest in subjects explored on those pages, such as LGBT community, black social issues, the Second Amendment, and immigration.”

The New York Times in 2015 reported that the Internet Research Agency was “known for employing hundreds of Russians to post pro-Kremlin propaganda online under fake identities, including on Twitter, in order to create the illusion of a massive army of supporters.”

Facebook chief security officer Alex Stamos on Wednesday said the company “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.”

“Our analysis suggests these accounts and Pages were affiliated with one another and likely operated out of Russia,” he said in a statement. “About one-quarter of these ads were geographically targeted.”

Stamos said in Facebook’s “latest review” the company “also looked for ads that might have originated in Russia — even those with very weak signals of a connection and not associated with any known organized effort.”

“This was a broad search, including, for instance, ads bought from accounts with US IP addresses but with the language set to Russian — even though they didn’t necessarily violate any policy or law,” he said. “In this part of our review, we found approximately $50,000 in potentially politically related ad spending on roughly 2,200 ads.”

A six-figure ad buy, though noteworthy given the investigation into Russian interference in the 2016 election, would be a very small fraction of what both candidates spent in battleground states during their campaigns.

Time magazine reported in May that U.S. counterintelligence officials discovered that Russian agents “bought ads on Facebook to target specific populations with propaganda,” though Facebook said at the time it had no evidence of such activity.

“They buy the ads, where it says sponsored by—they do that just as much as anybody else does,” an unnamed senior intelligence official told Time magazine.

Foreign nationals and governments are prohibited under federal law from “contributing, donating or spending funds in connection with any federal, state, or local election in the United States, either directly or indirectly.”

This post has been updated.