Facebook said it was in the process of removing some of the posts after being contacted by the Guardian, and said some had already been spotted and removed.

Dave Rich, the director of policy for the CST, which works to keep Jewish people safe from attack, said: “The sheer volume of IS-supporting accounts promoting terrorist content on Facebook is deeply alarming, and the posts celebrating the Bondi terrorist attack are utterly nauseating.

“Yet again, social media companies are incapable of meeting even their most basic of responsibilities and are putting all of us in danger as a result. This simply should not be happening any more. We will be calling on Ofcom to urgently investigate Meta’s failings and to take strong action where possible.”