Armed police may shoot terrorists behind the wheel to stop vehicles being used for terror attacks, a senior officer has said.
Terror attacks in Nice, Berlin and Westminster have exposed the damage attackers can inflict using lorries or cars to plough into hugely populated areas.
Simon Chesterman, the National Lead for Armed Policing, said terrorists keep adapting their tactics.
He said: "We've seen some very horrible and different tactics lately involving vehicles and lorries,"
"Within our policy, we used to talk about not shooting at a moving vehicle because of the danger we might cause if we fired at a driver.
"But if the vehicle is being used as a weapon in the first place, there aren't many tactics available in relation to stopping it, particularly a very large lorry.
"Driving a vehicle in front of it for example is not going to stop it. So you need to shoot the driver.
"As far as our training is concerned that's no different to any other tactics that we use and the weaponry that the officers carry now has the ability to penetrate doors, windows."
Getting the right ammunition to penetrate glass has been a challenge, Mr Chesterman said.
He added: "I'm confident with the work we've done, with the ammunition we carry, that an ARV (armed response vehicle) officer has the ability to fire at the cab of a lorry in order to bring it to a stop.
"But that's the only tactic really available internationally in terms of stopping it."
The possibility that vehicles could be used to inflict multiple casualties were confirmed in horrifying fashion in the Nice attacks in July last year when dozens of people were killed when a lorry ploughed into a large crowd watching a fireworks display to mark the Bastille Day holiday.
Months later an attacker drove a lorry into a crowded Christmas market in central Berlin, killing several people and injuring dozens more.
And last month Khalid Masood drove a car into pedestrians on Westminster Bridge during his murderous rampage.
Both Islamic State and Al Qaeda have previously urged followers to use vehicles to carry out attacks.