The Community Security Trust has said there is no suggestion that the Jewish community is at any greater risk than others, as the national threat level increased to ‘Critical,’ meaning an attack is “expected imminently”.

With the unnerving prospect of soldiers on the streets, the CST said it hadn’t waited to be told, saying: “We increased patrols and security cover immediately after the Manchester bombing, before it was confirmed as terrorism and before the national threat level was officially raised.”

Amidst the changes, security bosses said there would now be “heightened contact” between them and police and government security officials, as well as with the commercial guarding companies contracted to help protect sites.

“We will continue doing our utmost to ensure that all communal organisations fully comply with security advice,” said a spokesman. “We ask that our community be calm, but that it also be alert to potentially suspicious behaviour in and around Jewish buildings and areas.”

They asked community members to report anything suspicious either to the Police on 999 or to the anti-terror hotline 0800 789 321, or to CST’s national emergency 24-hour number 0800 032 3263.

“This is when our collective long-term investment in security is sadly shown to be necessary and we sincerely thank the community for the essential role that it plays in our work. This communal involvement is vital.”