Two major security investigations prompt nationwide arrests as government flags surge in hostile state activity
In one of Britain’s most significant national security operations in recent years, eight men, including seven Iranian nationals, have been arrested across England in connection with two separate counter-terrorism investigations, British authorities confirmed on Sunday.
The operations, which unfolded across London, Manchester, Rochdale, Stockport, Swindon, and other urban centres, have been described by Home Secretary Yvette Cooper as among “the biggest counter state threat and counter-terrorism operations that we have seen in recent years.”
Nationwide Sweep Targets Tehran-Linked Threats
The UK’s Metropolitan Police stated that the first of the two unconnected operations led to the arrest of five men aged between 29 and 40, four of whom are Iranian nationals. The men were apprehended on Saturday on suspicion of plotting to target unspecified premises in the UK.
The police declined to name the alleged targets but confirmed the arrests occurred across multiple regions, with ongoing efforts to determine whether there are further public safety risks.
“We are exploring various lines of enquiry to identify whether there may be any further risk to the public linked to this matter,” said Commander Dominic Murphy, head of the Met’s Counter Terrorism Command.
The nationality of the fifth man has not yet been disclosed.
Second Operation Cites National Security Act
In a separate, non-related operation, three additional Iranian nationals aged between 39 and 55 were arrested in London on suspicion of foreign power threat activity. These arrests were made under the National Security Act, legislation enacted in 2023 to strengthen the UK’s defences against hostile state actors.
All three suspects were detained on Saturday, with searches continuing at multiple addresses, according to a statement from the Metropolitan Police.
The Iranian Embassy in London has not commented on the arrests, and no charges have been officially filed as of Sunday evening.
Home Secretary: A Wake-Up Call on Hostile State Activity
Speaking to reporters, Home Secretary Cooper emphasized the growing complexity of national security threats, citing the “real and evolving danger” posed by foreign-backed actors.
“These two major operations reflect the complex challenges our national security agencies now face,” Cooper said. “This is about protecting the UK from both terrorism and hostile foreign interference.”
Her remarks echo warnings issued by MI5 Director General Ken McCallum, who in 2023 disclosed that since 2022, British intelligence had disrupted at least 20 Iran-linked plots, some of which posed lethal threats to UK-based individuals.
Rising Iran-Related Threats in the UK
The arrests come amid mounting evidence of Iranian state-linked operations within Britain. Key incidents include:
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2023: An Austrian national was convicted for conducting “hostile reconnaissance” outside the headquarters of Iran International, a London-based news outlet critical of the Iranian regime.
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2024: A British journalist of Iranian origin working for Iran International was stabbed in London, prompting renewed scrutiny of Tehran’s suspected extraterritorial activities.
The UK government has since placed Iran on the highest tier of its Foreign Influence Registration Scheme, compelling all political lobbying or influence operations linked to Tehran to be disclosed.
National Security Act Takes Centre Stage
The arrests under the National Security Act mark one of the most high-profile uses of the legislation since its introduction. The Act modernized Britain’s espionage laws, criminalizing foreign interference, covert influence campaigns, and unregistered foreign state activity.
Legal experts say Saturday’s arrests could represent a test case for how the law is enforced, particularly in cases involving alleged Iranian state involvement.
“The Act is designed for precisely this kind of threat landscape, where traditional lines between terrorism and espionage are increasingly blurred,” said one senior legal analyst specializing in national security law.
Implications for UK-Iran Relations
The arrests are likely to further strain diplomatic relations between London and Tehran, already tense over Iran’s proxy activities, sanctions violations, and detentions of dual nationals. Britain’s Foreign Office has not yet issued a formal statement.
Observers say the timing of the arrests—so close to the UK’s upcoming general election cycle—will only increase political scrutiny over domestic counter-intelligence capabilities and hostile state deterrence.
