On Thursday, Facebook said it had taken down a rapidly growing group where violent rhetoric and baseless claims that Democrats were stealing the election were posted by some supporters of US President Donald Trump.

The "Stop the Steal" group, which called for "boots on the ground to protect the integrity of the vote" on Thursday afternoon, added 1,000 new members every 10 seconds and in a single day had grown to 365,000 members.

"In a statement, a Facebook spokeswoman said," The group was organized around the delegitimization of the election process and we saw worrying calls for violence from some of the group's members.

She said that during "this period of increased tension," the move was in line with the "exceptional measures" Facebook was taking.

The “Stop the Steal” group had prepared for Facebook to take action, directing new members to an email sign-up page “in the event that social media censors this group”.

Another group using the same name, but with different administrators, told its members that no threats would be allowed and that they should take precautions like using images with words rather than text. This group, which had more than 2,000 members, also said it would shift to become private in a few days.

Public Facebook groups can be seen, searched and joined by anyone on Facebook, while only members can see posts in private groups.

Facebook has billed groups as community forums for shared interests but watchdog organisations and social media researchers have argued that they can be hotbeds for hyper-partisan misinformation.

“Facebook has been enabling and amplifying the infrastructure that’s now being used to attack our democratic process,” Arisha Hatch, executive director of the racial justice group Color Of Change, told Reuters News Agency.

Facebook, which normally recommends groups to users that they may want to join based on their activity on the site, last week suspended these recommendations for political groups and new groups around the election.

The now-removed “Stop the Steal” group was run by the Trump action group Women for America First. The non-profit organised protests against COVID-19 restrictions and supported Trump during his impeachment hearing.

On Twitter, one of the Facebook group’s administrators, Amy Kremer, said: “The left is trying to steal an election and Social media is complicit,” she said. “This is outrageous!”