Since last year, MI5 warned about “fatal and deadly” Iran-backed activities, it has been on high alert.
The UK has arrested eight men, including seven Iranians, as part of two investigations into alleged threats to national security.
London metropolitan police confirmed their arrests on Sunday, saying five men, including four Iranian citizens, have been detained on suspicion of “preparing for terrorist acts,” while three others have been detained under national security laws introduced in 2023 to counter hostile state actions.
In the first operation held on Saturday, counterterrorism police arrested four Iranians along with other individuals still-established nationalities in the London, Swindon and Manchester regions in connection with “substantiated conspiracy to target specific facilities.”
The five men were between 29 and 46 years old. Four Iranians were arrested under the Terrorist Act, while the fifth man was taken into custody under the Police and Criminal Evidence Act.
“This is a rapidly moving investigation,” added Dominique Murphy, Chief of the Metropolitan Police Department in Counter-Terrorism, adding that police “to explore various investigation lines to establish potential motivations and to identify whether there is further risk to the public related to the issue.”
In the second operation that same day, counterterrorism police arrested three Iranian citizens, ages 39, 44 and 55, in London under national security law.
Metropolitan Police said on Sunday that the three London arrests were “not related to the five arrests yesterday.”
Interior Secretary Yvette Cooper described the threat as “serious” and said the government is working with police and intelligence reporting agencies to “keep the country safe.”
The arrest came amid growing concern over Iran’s operations in British soil after the head of the UK’s MI5 national intelligence agency said last year that the UK had discovered 20 Iran-supported plots since 2022 that pose a “potentially fatal threat.”
In 2023, Austrians were found guilty of conducting “hostile reconnaissance” against Iran’s International London headquarters, a broadcaster critical of the Iranian government.
The following year, an Iranian British journalist working for Iran International was stabbed in London.
In February, a former British soldier was sentenced to 14 years in prison after being convicted of spying on Iran.
Iran repeatedly rejected the proposal that it was behind a plot to attack Britain.
In March, Tehran summoned the British ambassador in response to the accusations and presented a formal protest.
And in October, Iran’s Foreign Ministry spokesman Esmaeil Baghaei accused the UK of hosting a group of “terrorists” that promoted violence.