ProtectUK publication date
Guidance on Marauding terrorist attacks.


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

NPSA (formerly 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.


These are:

  • Announcements - alerting personnel using live and recorded announcements

  • Lockdown - considerations for locking doors to delay and frustrate attackers

  • Physical Barriers to Delay and Discourage Attackers – making the best use of low security features, such as doors.

  • Active Delay Systems – measures that can further delay the rate of progress of an attack

  • Preparing personnel - developing a programme to raise awareness and provide training to staff

  • Working with police and other emergency services - integrating your response with the emergency services and background on the emergency services’ response to an MTA

  • Testing and Exercising – detailing techniques to validate that your plans will work at the moment of need.

  • ASCEND: Improving organisational response to marauding terrorist attacks - a summary of key emerging themes from trials conducted between 2017 and May 2018

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

Further advice

For further information please contact your local police force Counter Terrorism Security Adviser or a NPSA (formerly CPNI) recognised security professional.

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MTA Guidance Making Your Organisation Ready

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MTA Guidance Active Delay Systems

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MTA Making Your Organisation Ready Busy Reader Booklet

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MTA Guidance Improving Organisational Response

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MTA Guidance Testing and Exercising

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MTA Guidance Lockdown

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MTA Guidance Preparing Personnel

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MTA Guidance Announcements

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MTA Guidance Working with Police and other Emergency Services

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MTA Guidance Physical Barriers to Delay and Discourage Attackers

Attack Methodology