LONDON The attack on a Berlin Christmas market showed the devastation that can be wrought by the simple act of driving a truck into crowds, and the problems in preventing another massacre.

The attack in Germany on Monday, in which 11 people were killed by the truck in addition to the murder of the Polish driver, mirrored a militant raid in the French city of Nice in July that killed 86.

Hauliers increasingly track their vehicles in real time but security experts say the technology cannot be used to stop an attack if a lorry has been hijacked to be used as a weapon.