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Marauding Terrorist Attacks

Marauding terrorist attacks are fast-moving, violent incidents where assailants move through a location aiming to find and kill or injure as many people as possible

Last Updated 28 April 2021


Marauding terrorist attacks (MTA) are fast-moving, violent incidents where assailants move through a location aiming to find and kill or injure as many people as possible. Most deaths occur within the first few minutes of the attack, before police are able to respond.

MTAs can take many forms and include a combination of the following:

  • A lone attacker, multiple attackers or multiple groups of attackers
  • Arrival at a location on foot, in a vehicle or an attack perpetrated by insiders
  • Entering without using force or forcing entry using an explosive device, a vehicle, coercion of someone with access or a combination thereof
  • Attackers armed with bladed weapons, firearms, pipe bombs, petrol bombs suicide vests or multiple weapons

Bladed weapon attacks progress less rapidly than those involving firearms since attackers must be within striking distance of their victims and expend more energy on each person.

It is more important than ever that your organisation is aware of the heightened risks and adequately prepared for any potential attack.

New and detailed guidance is now available providing information as to the range of measure that can be taken to minimise the impact of an attack and help save lives. These measures range from implementing simple changes to security processes and technical systems to introducing new and sophisticated security systems.


Marauding Terrorist Attacks: Making your organisation ready discusses how your organisation can recognise an attack, take immediate action and facilitate the police. It is most relevant to office buildings, including multiple tenancy buildings. However, the principles of the advice can be usefully applied to all types of locations including cinemas, hotels, hospitals, schools, shopping areas, shopping centres, stadiums, theatres, temporary event venues and transport hubs.

Basis of the guidance

The guidance has been written and based on:

  • Extensive analysis of previous MTAs in the UK and elsewhere around the world
  • Live simulations of marauding attacks involving hundreds of people to understand where responses can fail and test the effectiveness of training, procedures and security systems.
  • Reviews and discussions with businesses that have highlighted common issues.

Introducing the MTA Guidance

CPNI and NaCTSO have developed a series of guides to help your organisation assess the risk and implement a range of protective security mitigations. These guides are based on analysis and learning from MTAs that have taken place, live simulations of attacks and exercises and feedback undertaken with businesses.

The 10 guidance pieces are:

  • MTA: A Busy Reader’s Guide to Making Your Organisation Ready, which provides a high level summary of the key issues for senior managers.
  • MTA: Making your organisation ready, which is the principal guidance document setting out all of the protective security mitigations and considerations
  • MTA: Technical supplements, providing further information of specific topics that are important to effective defences.

This guidance also contains checklists contained in the documents, to help you establish next steps.

Front cover Marauding Terrorist Attacks: Supplementary guidance - Announcements

Alerting personnel using live and recorded announcements

Front cover Marauding Terrorist Attacks: Active delay systems

Measures that can further delay the rate of progress of an attack

Front cover Marauding Terrorist Attacks: Supplementary guidance - Lockdown

Considerations for locking doors to delay and frustrate attackers

Front cover Marauding Terrorist Attacks: Supplementary guidance - Testing and exercising

Detailing techniques to validate that your plans will work at the moment of need

Front cover Marauding Terrorist Attacks: Supplementary guidance - Preparing personnel

Developing a programme to raise awareness and provide training

Front cover ASCEND - Improving organisation response to Marauding Terrorist Attacks

A summary of key emerging themes from trials conducted between 2017 and May 2018

Marauding Terrorist Attack Standard (MTAS)

MTAS has been developed to reflect the range of forced entry threats faced by UK government, national infrastructure and crowded places. It provides a means for determining the delay (resistance time) of a physical barrier (product) against either: 

  • the use of bladed weapons to attack the physical barrier in order to achieve access through it; 
  • the use of firearms to attack the physical barrier followed immediately by a forced entry attempt using manually operated tools; or 
  • detonation of a small explosive device (improvised or plastic explosive) in contact with the physical barrier, or a person borne improvised explosive device (PBIED) in close proximity to the physical barrier, followed immediately by a forced entry attempt using manually operated tools. 

Guidance document Introduction to the Marauding Terrorist Attack Standard (MTAS) explains how the standard classifies the delay a product provides to such entry attempts by attributing one or more performance levels to a product.  The sophistication levels are BASIC, LOW, MODERATE, HIGH and EXPERT.

Products that achieved MTAS resistance classifications are listed in the following chapter’s within CPNI’s Catalogue of Security Equipment (CSE)

  • Doors, Tubestiles, Turnstiles (Note locking hardware on its own will not achieve MTAS.  Locking hardware has to be part of door etc)
  • Roller shutters
  • Walls and Enclosures
  • Window Protection

The CSE also contains a number of generic designs which are based on CPNI’s SME knowledge and research.

Further advice

For further information please contact your CPNI adviser, your local police force Counter Terrorism Security Adviser or a CPNI recognised security professional.

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