Facebook has taken down more than 100 accounts and pages for what it describes as “co-ordinated inauthentic behaviour”.
Nathaniel Gleicher, Facebook’s head of cybersecurity policy, said 137 accounts on Facebook and Facebook-owned Instagram were removed.
The accounts were part of a domestic-focused network in the UK, he added.
“The individuals behind these accounts represented themselves as far-right and anti-far-right activists, frequently changed page and group names, and operated fake accounts to engage in hate speech and spread divisive comments on both sides of the political debate in the UK,” Mr Gleicher said.
“Despite their misrepresentation of their identities, we found that these pages, groups and accounts were connected.
“They frequently posted about local and political news including topics like immigration, free speech, racism, LGBT issues, far-right politics, issues between India and Pakistan, and religious beliefs including Islam and Christianity.”
There were 23 Facebook pages, 74 Facebook accounts, five groups and 35 Instagram accounts taken down.
They had a combined 175,000 followers on Facebook and 4,500 on Instagram and contained names such as Anti Far Right Extremists, Atheists Research Centre, and Politicalised.
Mr Gleicher said: “We are constantly working to detect and stop this type of activity because we don’t want our services to be used to manipulate people.
“We’re taking down these pages and accounts based on their behaviour, not the content they posted.
“In each of these cases, the people behind this activity coordinated with one another and used fake accounts to misrepresent themselves, and that was the basis for our action.”
Facebook also took similar action against 31 accounts and pages in Romania for engaging in hate speech and making divisive comments.
Mr Gleicher said: “While we are making progress rooting out this abuse, as we’ve said before, it’s an ongoing challenge because the people responsible are determined and well funded.
“We constantly have to improve to stay ahead.
“That means building better technology, hiring more people and working more closely with law enforcement, security experts and other companies.
“Their collaboration was critical to these investigations.”
He added that the information had been shared with law enforcement and politicians in the UK.
The news comes a day after Facebook’s chief executive Mark Zuckerberg detailed his plans to make Facebook messages encrypted.