On March 6, London’s Metropolitan Police announced the arrest of four men suspected of surveilling locations and individuals related to both Iran and the Jewish community. The UK intelligence department had previously warned about Iran’s active spy operations in the UK.
According to the London police, among the four arrested individuals, one is of Iranian nationality while the other three hold dual British-Iranian citizenship. They were detained on suspicion of aiding a foreign intelligence agency.
The ages of the four men are 22, 40, 52, and 55 respectively, and they were apprehended in the early hours of Friday in Harrow, Watford, and Barnet near London.
Helen Flanagan, the Commander of the Counter Terrorism Police in London, stated, “We understand the public may feel concerned, especially the Jewish community. As always, we urge them to remain vigilant and contact us if they see or hear anything of concern.”
Counter terrorism police are conducting searches at the suspects’ residences and several other properties.
Furthermore, the authorities mentioned that six additional men (aged 20 to 49) were also arrested for aiding criminals at the residence of one of the suspects.
The day before, British Prime Minister Keir Starmer had stated, “Even in the UK, the Iranian regime poses a direct threat to dissidents and the Jewish community. Over the past year alone, they have supported over 20 potentially lethal attacks within the UK. Therefore, it is clear they must not be allowed to develop nuclear weapons.”
Prior to this incident, the UK intelligence agency MI5 had repeatedly warned about Iran’s active spy operations in the UK.
MI5 Director General Ken McCallum cautioned that the Iranian regime is the “most frequent violator crossing the terrorism threshold internationally” and is a “complex adversary.”
In October 2025, MI5 issued a rare public warning to British lawmakers, stating that Iranian, Russian, and Chinese intelligence operatives were attempting to influence UK political decisions through methods such as recruitment, manipulation, funding, and cultivating long-term relationships.
In March of this year, UK media outlet iNews reported that MI5 and British counter-terrorism officials revealed the existence of an Iranian “sleeper cell” within the UK. These individuals could be involved in assassinating Iranian dissidents, carrying out “lone wolf” attacks on UK targets, or conducting cyber attacks, with the UK seen as a “secondary but real retaliation target.”
Since 2022, the UK intelligence agency has foiled at least 20 Iran-related murder and kidnapping plots. Many of these cases are linked to a secret unit within the Revolutionary Guards known as Unit 840, yet the UK government has yet to dismantle this organization.
Media reports have detailed assassination activities carried out by Iranian intelligence agencies in the UK. An illustrative case is the 2022 “Wedding Conspiracy” where an Iranian intelligence unit provided $200,000 to a human trafficker to assassinate two news anchors of an Iranian diaspora TV network in the UK. These anchors were referred to as the “bride” and “groom” by the Iranian intelligence unit. The assassination plot was eventually thwarted by a double agent.
In 2024, an Iranian dissident journalist living in London was stabbed by two Romanian assailants recruited from Tehran outside his residence. He later fled to Israel to evade further threats from the assassins.
In May 2025, five Iranians were arrested on suspicion of planning a terrorist attack on the Israeli embassy in London.
During the same month, three Iranian men were charged with engaging in activities that may assist a foreign intelligence agency, with the investigation spanning from August 2024 to February 2025. The police explicitly stated that the foreign intelligence agency in question was from Iran. These three individuals had previously crossed the English Channel on a small boat to enter the UK and seek asylum.