A Twickenham bank was sealed off and temporarily closed after raiders robbed a security van outside.

The thieves struck such outside the Kings Street branch at 11am today with such speed neighbouring traders were not fully aware of what had happened.

The three man gang robbed the Group Four Security van as it made deliveries and police believe a woman guard was assaulted before they escaped with a cash box.

It understood they escaped in a silver family saloon car travelling in the direction of the Holly Road or Queen Street area.

John Bates, chief executive of the British Security Industry Association said: “This attack is yet another reminder of the serious nature of cash-in-transit robbery.

"Far from being a victimless crime, cash-in-transit attacks are perpetrated against men and women going about their everyday working lives performing an essential public service.”

Paul Kenny, GMB general secretary added: “We must not forget that every cash-in-transit attack has a human victim and we urge the Government to devote more police resources to the issue to ensure that both employees and the public, in these difficult times, are safe and secure.”

One of the suspects is described as black, another as white. There was no description for third. All wore distinctive yellow reflective jackets and no weapons were seen. The woman did not require hospital treatment.

Anyone with information should call Crimestoppers on 0800 555 111.