How many suspected extremists were referred to the UK's Prevent program for school massacre plots?

Between 2021 and 2024, 475 individuals feared to be capable of committing a 'school massacre' were referred to the Prevent program.

What is the definition of a 'mass casualty attack' referral in the UK?

A 'mass casualty attack' referral is a newly adopted definition for individuals deemed to pose a threat of such attacks, with 469 such referrals in the year to March 2025.

Who typically refers individuals to the Prevent program for extremist threats?

Individuals are usually referred to Prevent by teachers, social workers, friends, and family members.

Home / Crime and Justice / UK Terror Watchlist: 900+ Suspected Attackers

UK Terror Watchlist: 900+ Suspected Attackers

14 Dec, 2025

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Summary

Over 900 extremists flagged for mass casualty or school massacre plots.
201 individuals were adopted for safeguarding and deradicalisation.
Most referrals come from secondary school teachers, often with good intentions.

UK Terror Watchlist: 900+ Suspected Attackers

Recent Home Office data indicates that more than 900 individuals suspected of plotting mass casualty or school massacre attacks were identified over the past four years. Between 2021 and early 2025, around 160 individuals per year were referred to the UK's Prevent programme for potentially planning 'school massacres.'

In the year leading up to March 2025, referrals for 'mass casualty attacks' surged to 469. This significant increase is partly attributed to heightened awareness following the Southport attack and a popular Netflix drama. Of the 944 individuals referred, 201 were escalated to local authority safeguarding groups for deradicalisation efforts.

While most referrals are dismissed, some individuals were arrested for possessing weapons intended for attacks, such as a 15-year-old found with multiple weapons. Notably, the perpetrator of the Southport attack, who murdered three young girls, had been referred to Prevent multiple times but was not deemed an extremist at the time.