Theresa May announced that the country’s threat level would move to its highest level yesterday evening in the wake of Monday night’s bomb attack in Manchester which killed 22 and injured 59.
Military personnel will now be deployed to protect key sites like main railway stations and government buildings.
Included on the list are Buckingham Palace, Downing Street, the Palace of Westminster and embassies.
Military personnel, who are expected to be deployed in their hundreds, will also patrol major events, from concerts to rugby matches, in the coming weeks.
However, home secretary Amber Rudd said she expects the critical level to be a temporary measure.
