The company said that the specific pages were trying to influence the U.S. midterm elections, using inauthentic accounts and pages on the social network.

"We're still in the very early stages of our investigation and don't have all the facts -- including who may be behind this," Facebook said Tuesday. "It's clear that whoever set up these accounts went to much greater lengths to obscure their true identities than the Russian-based Internet Research Agency has in the past."

About two weeks ago, Facebook says it identified the first of eight Pages and 17 profiles on Facebook, as well as seven Instagram accounts, that violate the company's ban on coordinated inauthentic behavior. Facebook removed all of them this morning and shared the information with US law enforcement agencies, Congress, other technology companies, and the Atlantic Council's Digital Forensic Research Lab, a research organization that helps us identify and analyze abuse on Facebook.

• In total, more than 290,000 accounts followed at least one of these Pages, the earliest of which was created in March 2017. The latest was created in May 2018.
• The most followed Facebook Pages were "Aztlan Warriors," "Black Elevation," "Mindful Being," and "Resisters." The remaining Pages had between zero and 10 followers, and the Instagram accounts had zero followers.
• There were more than 9,500 organic posts created by these accounts on Facebook, and one piece of content on Instagram.
• They ran about 150 ads for approximately $11,000 on Facebook and Instagram, paid for in US and Canadian dollars. The first ad was created in April 2017, and the last was created in June 2018.
• The Pages created about 30 events since May 2017. About half had fewer than 100 accounts interested in attending. The largest had approximately 4,700 accounts interested in attending, and 1,400 users said that they would attend.