Facebook believes about 10 million American users viewed targeted ads purchased by a group affiliated with the Russian government designed to sow political divisions ahead of the 2016 U.S. presidential election.

The company disclosed the new information after turning over the roughly 3,000 ads over to congressional committees investigating Russia’s interference with the election. The ads appear to have come from a Russian entity known as the Internet Research Agency.

Facebook didn’t release the ads publicly, but as it has said previously the ads weren’t tied to individual candidates. The company described most of the ads as focusing on “divisive social and political messages across the ideological spectrum.” The subjects of the ads spanned issues including LGBT, race, immigration and gun rights and many of them encouraged people to follow Facebook Pages on these issues.

Rep. Adam Schiff (D-Calif.), the ranking member of the House Intelligence Committee, said he hopes to release “a representative sampling” of the ads when tech firms testify at a public hearing before Congress. He also said he was “committed to making all of these ads public as soon as possible, working closely with Facebook to address any privacy considerations.”

On Monday, the world’s biggest social platform announced plans to hire an additional 1,000 employees to review ad submissions, along with other new policies and procedures designed to improve the transparency of Facebook’s advertising biz.

Facebook’s role in the controversy over Russian meddling in the American election has put the Silicon Valley giant and its business practices in a harsh spotlight — and elicited an attack from President Donald Trump, who tweeted that “Facebook has always been anti-Trump.” Facebook chief Mark Zuckerberg responded with a defense of the company’s platform as a place for political discourse.

Of the Russian-bought ads that were served on the platform, about 44% of total ad impressions occurred before the U.S. election on Nov. 8, 2016, and 56% came after the election. Around 25% of the ads were never shown to anyone — because the targeting criteria didn’t match any users, according to Facebook.

All told, Facebook says it sold $100,000 worth of ads linked to the Russian group. For 99% of the ads, less than $1,000 was spent (and for half of them less than $3 was spent).

Why didn’t Facebook catch the Russian political ad buys? The company in part blamed its massive scale, claiming that about 8 million people report ads to Facebook on a daily basis. In addition, while some of the ads were paid for in Russian currency, that wasn’t a good indicator of improper activity because “the overwhelming majority” of ads bought in Russian currency are from advertisers that “aren’t doing anything wrong,” Elliot Schrage, Facebook’s VP of policy and communications, wrote in a blog post.

As part of its policy changes, Facebook will now manually review advertising with “certain types of targeting,” according to Schrage. “There are worthwhile uses of ad targeting because they enable people to connect with the things they care about,” he wrote. “But we know ad targeting can be abused, and we aim to prevent abusive ads from running on our platform.”

Facebook noted, however, that if many of the ads in question had been bought by “authentic” individuals or organizations, it would have permitted them to run. By the same token, “If Americans conducted a coordinated, inauthentic operation — as the Russian organization did in this case — we would take their ads down, too,” Schrage wrote.

Facebook also said it is possible is has not uncovered all illegitimate ads related to the 2016 election that were bought on the platform and that it’s continuing to investigate. “We hope that by cooperating with Congress, the Special Counsel and our industry partners, we will help keep bad actors off our platform,” Schrage wrote.

Ultimately, Facebook will continue to host content that “people will find objectionable, and that we will find objectionable,” he continued. “We permit these messages because we share the values of free speech — that when the right to speech is censored or restricted for any of us, it diminishes the rights to speech for all of us.”

Ted Johnson contributed to this report.