Terrorist attacks in venues and public spaces - explosive devices

This risk is featured in the full matrix, representing the averages of multiple different scenarios presented together in the ‘terrorist attacks in publicly accessible locations’ category.

Impact 5
risk indicator
ID 3
Risk theme Terrorism
Impact & Likelihood
Impact key
5 Catastrophic
4 Significant
3 Moderate
2 Limited
1 Minor
Likelihood key
5 >25%
4 5-25%
3 1-5%
2 0.2-1%
1 <0.2%


An explosive attack can occur as a result from either a person-borne improvised explosive device, an emplaced improvised explosive device or vehicle-borne improvised explosive device. Examples of explosive attacks that have taken place in the UK include the 2017 Manchester Arena attack where a terrorist killed 22 people and the Liverpool Women’s Hospital explosion in 2021. The government continues to reduce the vulnerability of the UK to an explosive attack through restricting access to explosives precursor chemicals, improving detection capabilities including the introduction of National Canine Training and Accreditation Scheme for Private Companies, and maintaining an understanding of the explosive materials and methods that pose a risk in the UK.


The reasonable worst-case scenarios included in this category of risk include the detonation of an improvised explosive device (on a person, vehicle or emplaced) at an enclosed or unenclosed location with high crowd densities. These scenarios would result in multiple fatalities and casualties and there may be further fatalities and casualties through structural collapse (enclosed areas), fire/smoke or large numbers of people fleeing a scene to safety. An attack may temporarily impact utility supply, transport services and put pressure on emergency services.

Response capability requirements

The use of the Joint Emergency Services Interoperability Principles provides the basis for a coherent multi-agency response. The response to an explosion may utilise the deployment of both specialist and non-specialist responders. Local Resilience Forums and their Scottish and Northern Irish equivalents would support wider consequence management. Specialist response capabilities would include Explosive Ordnance Disposal and Urban Search and Rescue, which would be required for building collapse or structural damage to buildings. Support from utility providers may also be required if damage from the explosion damages underground cables and pipes. The Forensic Explosives Laboratory provides specialist forensic capabilities, which allows the prosecution of explosives-related crimes, including terrorism.


Local, regional and national victim support structures will be required to support all those impacted. The short-term excessive demands on hospitals may lead to delays in the system for several weeks. There would be a potential impact, in the medium term, on the tourism industry and businesses in affected areas. In some incidents the physical damage to structures may be extensive and areas may be out of action for a significant amount of time. Such an attack may also impact temporarily on utility supply to the surrounding areas. Residential properties in the vicinity may also be damaged, meaning that people are displaced for a period of time.