SAN FRANCISCO — Facebook on Wednesday said it has removed hundreds of groups tied to the far-right QAnon conspiracy theory and imposed restrictions on nearly 2,000 more as part of a crackdown on stoking violence.

The moves, which were made across both Facebook and Instagram, were against accounts tied to "offline anarchist groups that support violent acts amidst protests, US-based militia organisations and QAnon", the social media platform said in a blog post.

More than 790 groups, 100 pages, and 1,500 ads tied to QAnon were pulled from Facebook and more than 300 hashtags were blocked across the social network and Instagram, according to the post.

In addition, restrictions were placed on more than 1,950 groups and 440 pages on Facebook and more than 10,000 Instagram accounts, the social network said.

Facebook said it has also removed more than 980 groups and restricted hashtags related to militia organisations and "those encouraging riots".

Facebook additionally announced it was expanding rules against groups and movements that it said "have demonstrated significant risks to public safety but do not meet the rigorous criteria to be designated as a dangerous organisation and banned from having any presence on our platform".

The social network already bans content calling for violence and organisations that proclaim violent missions.

The platform has seen growth in movements that celebrate violence or weapons and hint at using them but stop short of directly organising any action, Facebook said.

Under the updated policy, Facebook aims to limit the spread of violating content and remove pages, groups and accounts hosting discussion of potential violence, even if veiled language and symbols are used to do so.

"These movements and groups evolve quickly, and our teams will follow them closely and consult with outside experts so we can continue to enforce our policies against them," Facebook said.

Twitter in July cracked down on QAnon as the loose-knit group increased its reach into the mainstream of US politics.

From an anonymous 2017 posting claiming bizarre child exploitation and deep state plots, the headless and bodiless movement has earned a place in Trump's Twitter stream.

Twitter's decision to shut down some 7,000 accounts pushing QAnon material came amid rising concerns that the movement could spawn violence.

The FBI last year said in a report that QAnon was one of several movements that could drive "both groups and individual extremists to carry out criminal or violent acts". — AFP