Facebook says accounts used by a right-wing Brazilian activist group were removed for spreading misinformation.

Facebook, Inc has deactivated pages and accounts used by a right-wing Brazilian activist group, cracking down on what it called a misinformation network ahead of elections in October.

Facebook said in a statement on Wednesday that it blocked 196 pages and 87 accounts in Brazil for their part in “a coordinated network that hid behind fake Facebook accounts and misled people about the nature and origin of its content, all for the purpose of sowing division and spreading misinformation.”

The statement did not identify the pages or users involved, and a Facebook representative declined to identify them.

However, sources told news agency Reuters that the network was run by senior organisers from the Movimento Brazil Livre (MBL) or “Free Brazil Movement.”

The MBL later said in a statement on Twitter that several of its organisers had been affected.

Translation: In this Soviet purge, Facebook has deleted my personal profile and, with it, my account management account with more than $400 already deposited. If I can not join the network, how do I take my money? That’s racketeering, they’ll answer in court, Thomaz H Barbosa, coordinator of MBL, wrote.

Neste expurgo soviético, o Facebook deletou o meu perfil pessoal e, com ele, minha conta de gerenciamento de anúncios com mais de R$400 já depositados. Se eu não posso participar da rede, como tomam o meu dinheiro? Isso é estelionato, vão responder na justiça. — Thomaz Henrique Barbosa (@othomazhenrique) July 25, 2018

The group rose to prominence in 2016, leading protests demanding the impeachment of leftist former President Dilma Rousseff with an aggressive style of online politics that has helped polarise debate in Brazil.

MBL representatives did not respond to multiple requests for comment. Their statement criticised Facebook for blocking several organisers without giving a full explanation, complaining that some of the banned accounts were using members’ real names and personal information.

“Freedom of expression and democracy are pillars of the MBL. We will use all of the legal, political and media resources offered by democracy to recover the blocked pages and undo this persecution,” the group said.

Facebook declined to comment on the criticism.

‘Rigorous investigation’

The deactivated pages, which together had more than half a million followers, ranged from sensationalist general news feeds to political fare with an openly conservative slant, carrying names such as Jornalivre and O Diario Nacional, according to media reports.

By misrepresenting the shared control of the pages, the MBL organisers were able to spread their coordinated messaging as if it were coming from various independent news outlets, sources who spoke on condition of anonymity said.

Facebook said it took down the network in Brazil after a “rigorous investigation” because the profiles involved were false or misleading, violating its authenticity policies. The social network has a separate set of tools to discourage the distribution of fake news with help from outside fact checkers.

Facebook has been under heavy pressure to stop the use of fake accounts and other types of deception on its network.

The company last year acknowledged that the platform had been used for what it called “information operations” – employing fake accounts and other methods to influence public opinion during the US election in 2016 – and pledged to crack down.