Hundreds of fake Facebook accounts, probably run from Russia, spent about $100,000 on ads aimed at stirring up divisive issues such as gun control and race relations during the 2016 U.S. presidential election, the social network said Wednesday.Although the number of ads is relatively small, the disclosure provides a more detailed peek into what investigators believe was a targeted effort by Russians to influence U.S. politics during the campaign, this time through social media.The 470 accounts appeared to come from a notorious "troll farm," a St. Petersburg-based organization known for promoting pro-Russian government positions via fake accounts, according to two people familiar with the investigation. The people were granted anonymity because they weren't authorized to publicly discuss details of the investigation.In all, the accounts purchased about 3,000 ads between June 2015 and May 2017. Though the ads didn't specifically reference the election, a candidate or voting, they nevertheless allowed "divisive messages" to be amplified via the social media platform, the company's chief security officer, Alex Stamos, said in a statement.Facebook has turned over its findings to federal authorities investigating Russian interference in the U.S. presidential election. Robert S. Mueller III, the special counsel, is charged with overseeing the probe into Russian meddling in the U.S. election and any potential coordination with associates of President Trump.Sen. Mark Warner of Virginia, the ranking Democrat on the Senate Intelligence Committee, said Facebook briefed the panel's staff on Wednesday, but he still wants to know more."I have a lot more questions for Facebook, and I've got a lot of questions for Twitter," Warner said, noting that "we've got Twitter coming in." He did not say when a meeting with representatives from Twitter might occur other than "soon."A spokeswoman for Twitter declined comment Wednesday evening.Warner said he also wants to know more about the content of the ads pushed out by the Russian-based Internet Research Agency and whether they targeted specific voters or locations in the U.S.He said in many cases the social media messaging "was more about voter depression and suppression without having to necessarily mention an individual candidate's name."Rep. Adam Schiff of Burbank, the top Democrat on the House Intelligence Committee, said Facebook's disclosure confirmed what many lawmakers investigating Russian interference in the U.S. election had long suspected."One of the things that we're interested obviously in finding out is whether there was any coordination in terms of the use of those paid social media trolls or the Russian use of bots," he said.The fake accounts were discovered during a company review of ad buys that was spurred by a broader investigation the company initiated into Russian meddling after the election, Stamos said.In addition to the 470 accounts that appeared to be run from Russia, Stamos said Facebook's investigators also discovered an additional $50,000 in spending via 2,200 ads that "might have originated in Russia," even including ads purchased by accounts with IP addresses in the U.S. but set to Russian in the language settings.The dollar amount of ad spending identified by Facebook is an infinitesimal amount compared with the total amount of advertising spending during the election. According to ad tracker Borrell Associates, more than $1.4 billion was spent during the 2016 election cycle on digital advertising alone. That figure includes spending on national, state and local elections.Rep. Eric Swalwell (D-Dublin), who also serves on the House Intelligence Committee, said Facebook's disclosures help to "fill in with more color some of the lines that exist," but he would like to know more about the sophistication of the ads. He also wants to know if the content of the ads smacked of Russian propaganda."We know they had a cyber operation, we suspect U.S. persons may have been involved, now we know a U.S. company was used. So now we need to see if there are dots that connect," he said.The company has come under intense pressure since the election to curb the flow of false information. After the election, it updated its advertising policy to say it wouldn't run spots that are "illegal, misleading or deceptive, which includes fake news."