Decades of planning helped to ensure security at Queen’s funeral, says expert

Police officers stand guard in London in the hours before the Queen’s funeral on Monday. Photograph: Alkis Konstantinidis/AP

The success of the enormous security operation surrounding the Queen’s funeral followed decades of intricate planning and heightened public vigilance, a counter-terrorism expert has said.

Royalty, world leaders and hundreds of thousands of members of the public were kept safe on Monday, amid heightened concerns over possible attacks.