Country on high alert since MI5 warning last year about ‘potentially lethal’ Iran-backed activities.
The United Kingdom has arrested eight men, including seven Iranian nationals, as part of two investigations regarding alleged threats to national security.
London’s Metropolitan Police confirmed the arrests on Sunday, saying five men, including four of the Iranian nationals, were detained on suspicion of “preparation of a terrorist act” while the other three are being held under national security legislation introduced in 2023 to counter the actions of hostile states.
In the first operation, which took place on Saturday, counterterrorism police arrested four Iranians along with the other individual, whose nationality was still being established, in London, Swindon and the Greater Manchester area in relation to “a suspected plot to target a specific premises”.
The five men were aged 29 to 46. The four Iranians were arrested under the Terrorism Act while the fifth man was detained under the Police and Criminal Evidence Act.
“This is a fast-moving investigation,” Metropolitan Police counterterrorism chief Dominic Murphy said, adding that police were exploring “various lines of enquiry to establish any potential motivation as well as to identify whether there may be any further risk to the public linked to this matter”.
In the second operation, which took place on the same day, counterterrorism police arrested three Iranian nationals aged 39, 44 and 55 in London under the National Security Act, which gives law enforcement greater powers to disrupt “state threats”, including foreign interference and espionage.
The Metropolitan Police said on Sunday that the three London arrests were “not connected to the arrest of five people yesterday”.
Home Secretary Yvette Cooper described the threats as “serious”, saying the government was working with police and intelligence agencies to “keep the country safe”.
The arrests were made amid heightened concerns about Iranian operations on UK soil after the head of Britain’s MI5 domestic intelligence service said last year that the UK had uncovered 20 Iran-backed plots posing “potentially lethal threats” since 2022.
In 2023, an Austrian national was convicted of carrying out “hostile reconnaissance” against the London headquarters of Iran International, a broadcaster that is critical of Iran’s government.
The following year, a British journalist of Iranian origin who worked for Iran International was stabbed in London.
In February a former British soldier was sentenced to 14 years in prison after being found guilty of spying for Iran.
Iran has repeatedly rejected suggestions that it has been behind plots to attack the UK.
In March, Tehran summoned the British ambassador in response to the accusations and conveyed a formal protest.
And in October, Iranian Ministry of Foreign Affairs spokesperson Esmaeil Baghaei accused the UK of hosting “terrorist” groups that promote violence.