London: In the frantic minutes after police shot dead knife-wielding terrorist Sudesh Amman in a busy high street, an armed officer walked into a nearby cafe with a simple instruction.

A police officer orders the evacuation of a cafe near the Streatham terrorist attack. Credit:Twitter

"Sorry guys, you're going to have to close and evacuate I'm afraid. There's been a terrorist incident down there," he said. "If you want to stay safe you'll listen to me."

An incredulous staff member replied: "Just give us half an hour? People have started to eat."

"Madam, a terrorist has been shot dead just down there," the officer responded. "They've got a possible IED vest on them, which is a bomb. If you want to try to stay open for half an hour and you want to put people's lives in danger, then be my guest. If not, please listen to me and please make your way out of the shop."