In a blog post on Wednesday, Facebook chief security officer Alex Stamos said that the company was reviewing a range of activity on its platform to investigate the serious claims that Russian interference could be tied to Facebook.
Facebook said it shut down accounts involved that were still active.
The ad sales were found as part of an internal investigation, the Post reports.
But while Facebook may be able to limit what people can and can't buy on its platform, it doesn't change the fact that social media has created a stage for anyone looking to spread false information online, with or without ads.
These fake news pages and ads were found during a Facebook investigation this spring that looked into purchases of politically motivated advertisements.
"[We] looked for ads that might have originated in Russian Federation, even those with very weak signals of a connection and not associated with any known organized effort". However, according to official United States census data, there should only be 31m people of that age in the country.
News of Facebook's discovery came on the same day Facebook was accused of inflating its advertising reach.
In 2013, hackers released internal company documents showing it employed 600 people across Russian Federation. 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.
In its unclassified report in January, the USA intelligence community concluded that the Internet Research Agency's "likely financier" is a "close Putin ally with ties to Russian intelligence".
Given the deep knowledge of state-level American politics necessary to successfully geo-target ads like these, the whole thing raises further questions about the possibility that entities linked to the Russian government might have coordinated with individuals in the US, though it doesn't begin to answer those questions. The ban includes independent expenditures made in connection with an election.