Facebook has removed a network of more than 100 accounts and pages for “coordinated inauthentic behaviour” on its social networks – the first time it has done so for UK-based operations seeking to influence British citizens.

The operation was spread over Facebook and Instagram and used a network of fake accounts to pose as both far-right activists and their opponents. It ran pages and groups whose names frequently changed in order to drum up more followers and operated fake accounts to engage in hate speech and spread divisive comments on both sides of UK political debate, Facebook says.

The pages, with names like “Anti Far Right Extremists”, “Atheists Research Centre”, and “Politicalised”, attracted about 175,000 followers on Facebook, and a further 4,500 on Instagram, according to the company’s head of cybersecurity policy, Nathaniel Gleicher.

“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,” Gleicher said. “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.

“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.”

According to Ben Nimmo of the Atlantic Council, an independent digital forensic research lab, the operation was apparently intended “to counter far-right representations of Muslims, LGBT communities and minorities in the UK”.

The pages shared content from mainstream news sources, such as the BBC and the New York Times, but also shared original content, even including administrators actively engaging in debate with users.

The removals come the day after Facebook’s chief executive, Mark Zuckerberg, published a lengthy memo about the company becoming a “privacy focused social network”, by emphasising direct messaging and end-to-end encryption above public sharing. That shift could make enforcement operations harder to carry out in the future, Gleicher admitted.

“Obviously part of what you saw in Mark’s note is that the thinking about how we move towards privacy-focused work is early and we’re developing it. That tension is something we’re going to be discussing.

“Ensuring we’re able to provide safety on the site and carry on doing the sort of investigations we do is something Mark did address,” Gleischer added.

Zuckerberg had written that the move to a newly privacy-focused social network “would create safety and spam vulnerabilities in an encrypted system to let people send messages from unknown apps where our safety and security systems couldn’t see the patterns of activity.”