Vehicle-borne improvised explosive devices (VBIEDs)

Vehicle bombs are one of the most effective weapons in the terrorists' arsenal. These bombs are capable of delivering a large quantity of explosives to a target and can cause a great deal of damage.

In general, vehicle bombs fall into three categories:

• large vehicle-borne improvised explosive device (LVBIED). An LVBIED is a lorry or truck filled with explosives. These vehicles enable terrorists to carry very large amounts of explosives, possibly several tonnes, to a target and cause casualties and destruction over a range of hundreds of metres
• vehicle-borne improvised explosive device (VBIED). A VBIED is a car or van filled with explosive, driven to a target and then detonated.
• under vehicle improvised explosive device (UVIED). A UVIED is a type of small, 'booby-trap' improvised explosive device placed in, on, or under a vehicle, and designed to explode when the vehicle moves.

Vehicle bombs typically use an improvised explosive; sometimes a flammable substance is added to enhance the effect e.g. liquefied petroleum gas (LPG). The bomb can be made in advance at a safe location some distance from the target. The explosive may be in the load-carrying area of the vehicle, concealed in the chassis or behind panels, or in one or more containers such as beer kegs, dustbins, wheelie bins or large suitcases.

Once assembled, the bomb can be delivered at a time of the terrorists' choosing and with reasonable precision, depending on defences. It can be detonated from a safe distance using a timer or remote control, or detonated on the spot by a suicide bomber.

Building a vehicle bomb requires a significant investment of time, resources and expertise. Because of this, terrorists will seek to obtain the maximum impact for their investment. They generally choose high-profile targets where they can cause the most damage, inflict mass casualties and attract widespread publicity.

What you can do

• ensure that an identified individual is responsible for security and that the police know your plans and the layout of your building
• employ basic good housekeeping such as vehicle access controls and parking restrictions
• consider using physical barriers to keep all unauthorised vehicles at a safe distance. Seek police advice on what these barriers should be and on further measures such as electronic surveillance
• where possible, vehicles that are permitted to approach your building should be authorised in advance and searched. The identity of the driver should also be cleared in advance
• consider the effectiveness of your communications and announcement systems - you may need further technical advice
• do what you can to make your building more blast resistant, paying particular attention to windows. Establish and rehearse bomb threat and evacuation drills. Bear in mind that, depending on where the suspected vehicle bomb is parked and the design of your building, staff may be safer in windowless corridors or basements than outside. Assembly areas for staff must take account of the proximity to the potential threat. A vehicle bomb delivered into your building - for instance via underground car parks or through the front of your premises - could have a far greater destructive effect on the structure than an externally detonated device
• train and rehearse your staff in identifying suspect vehicles, and in receiving and acting upon bomb warnings. Key information and telephone numbers should be prominently displayed and readily available
• have the building reviewed by a qualified security engineer or adviser when seeking advice on protected spaces.