The social media site Facebook has taken down 32 pages and accounts over what it calls "coordinated inauthentic behaviour".
Some of the removed pages also relate to photo-sharing site Instagram, which Facebook owns.
In a statement, the company says: "This kind of behaviour is not allowed on Facebook because we don't want people or organisations creating networks of accounts to mislead others about who they are, or what they're doing.
"We're still in the very early stages of our investigation and don't have all the facts - including who may be behind this.
"But we are sharing what we know today given the connection between these bad actors and protests that are planned in Washington next week."
These protests are coming just ahead of US mid-term elections in November.
The New York Times reports that the accounts and pages "are believed to be engaging in political activity ahead of November's midterm elections".
One of the pages shut down by Facebook | Image: Facebook
Facebook says: "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 (IRA) has in the past.
"We believe this could be partly due to changes we’ve made over the last year to make this kind of abuse much harder.
"But security is not something that’s ever done. We face determined, well-funded adversaries who will never give up and are constantly changing tactics.
"It's an arms race and we need to constantly improve too. It’s why we’re investing heavily in more people and better technology to prevent bad actors misusing Facebook - as well as working much more closely with law enforcement and other tech companies to better understand the threats we face."
Facebook's head of cybersecurity policy, Nathaniel Gleicher, says: "About two weeks ago we identified the first of eight pages and 17 profiles on Facebook, as well as seven Instagram accounts, that violate our ban on coordinated inauthentic behaviour.
"We removed all of them this morning once we'd completed our initial investigation 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 analyse 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.
One of the events shut down by Facebook | Image: Facebook
The most followed Facebook pages were 'Aztlan Warriors,' 'Black Elevation,' 'Mindful Being,' and 'Resisters.'
There were more than 9,500 organic posts created by these accounts on Facebook, and one piece of content on Instagram.
Mr Gleicher adds: "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.
"We are still reviewing all of the content and ads from these pages."
The 'Resisters' page also created a Facebook event for a protest on August 10th to 12th, and enlisted support from real people.
A message for people due to attend an event shut down by Facebook | Image: Facebook
Mr Gleicher explains: "Inauthentic admins of the 'Resisters' page connected with admins from five legitimate pages to co-host the event.
"These legitimate pages unwittingly helped build interest in 'No Unite Right 2 - DC' and posted information about transportation, materials, and locations so people could get to the protests."
The event has been disabled, and Facebook has reached out to the admins of the five other pages to update them on what happened.
The company is also informing the approximately 2,600 users who were interested in the event, and the more than 600 users who said they would attend, about what happened.
