Armed counter-terrorism police will use motorcycles in response to an attack in London.

The bikes will allow them to reduce response times by beating gridlocked traffic in the capital.

Armed officers will ride pillion on grey BMW F800GSs, going off-road or mounting kerbs where necessary to get to an attack more quickly.

An elite counter-terrorism officer told Sky News: "Traffic can be gridlocked at the best of times - certainly in the times of an attack.

"If you look at Europe, at Paris and Belgium, traffic becomes a major impingement on a rapid response.

"We've looked at tactics and pillion riding with motorcycles gives us a very fast and effective response. The guys practise riding off road so they can bump up and down across pavements and make really good progress from A to B."

The tactic was revealed as more armed officers are deployed across London from today, following attacks in France and Germany.

The operation is not based on a specific threat but aimed at making London "as hostile an environment as possible" for would-be attackers.