British authorities are investigating a suspected plot targeting a military base used by the United States in strikes against Iran, an incident that Washington and London have suggested could involve Tehran.
Police arrested five men, all in their mid-20s, and released them on bail under “strict conditions” while the investigation continued. British national security laws give authorities considerable leeway to detain terrorism suspects for longer periods.
Britain’s counterterrorism authorities said they were examining all possibilities, including whether the individuals may have been acting on behalf of a foreign state. They said that “An Iranian-linked motive is considered the most likely.”
British authorities have not confirmed that the incident was an act of terrorism or that Iran was behind it, stressing that the investigation remains open to all possibilities.
The timing and location of the incident have drawn particular attention, coming after previous Iranian threats to regard any British base used in operations against Iran as a legitimate target.
U.S. President Donald Trump told reporters at the White House on Monday that the incident could be linked to Iran and that the suspects had intended to cause “big damage.” Commenting on the suspects release on bail, Trump said, “I wouldn’t have done that.”
Secretary of State Marco Rubio told Fox News that “what happened, what almost happened, what could have happened in the UK over the weekend is a very serious situation. It’s one that clearly involves the hands of a foreign actor.”
British authorities received reports Sunday of three “suspicious” white trucks near RAF Fairford, a Royal Air Force base in western England.
Laurence Taylor, the head of Britain’s counterterrorism police, told reporters in London that “officers are pursuing multiple lines of inquiry, including if proxies working on behalf of a foreign state could’ve been involved.”
According to police, the men were arrested on suspicion of offenses involving explosives and preparation of an act of terrorism under Britain’s counterterrorism laws.
Tehran has categorically denied the allegations through its embassy in London, saying it “strongly condemns the recent unfounded and malicious speculations.”
The base is significant because it is one of the few air bases in Europe used by the United States and equipped to accommodate heavy bombers. It played a central role during the 1991 Gulf War and the 2003 Iraq War.
U.S. forces used Fairford this year to launch strikes against Iran, including operations involving B-1 and B-52 bombers.
Britain said in July that its armed forces were prepared to protect RAF Fairford after Iran’s Islamic Revolutionary Guard Corps warned Britain against allowing U.S. bombers to take off from the base.
In March, at the height of the war between Iran, the United States and Israel, counterterrorism experts warned of the risk of potential Iranian attacks and acts of sabotage carried out through proxies, extremists or criminals.
U.K. Foreign Secretary Ed Miliband said Monday that the incident is a “reminder of the threats our country faces.”
Miliband met Iranian Foreign Minister Abbas Araghchi at the United Nations in New York last week and told him that “Britain will not tolerate intimidation, threats or hostile activity on U.K. soil,” according to a British statement on the meeting.
The latest incident comes after British intelligence warned that both Iran and Russia have used proxies to carry out activities on British soil.
British officials said in March that the number of national security cases linked to the activities of hostile states, including Iran, had risen by 50 percent in the six months ending in December 2025.
Jason Brodsky, a nonresident scholar with the Middle East Institute’s Iran Program, told MBN that there are indications of Iranian involvement in the incident, noting that individuals linked to Iran had been arrested in recent months while allegedly attempting to conduct surveillance on other bases connected to the war effort, particularly in Cyprus.
Historical precedents indicate that Iran-linked proxies have been behind numerous assassination and sabotage attempts in Britain and elsewhere, with the scope of such threats expanding as conflicts in the Middle East have continued.
Since 1984, successive U.S. administrations have designated Iran as a “state sponsor of terrorism.” The Islamic Revolutionary Guard Corps and its overseas arm, the Quds Force, operate extensive networks of armed proxies, operatives and sleeper cells to carry out such campaigns.
The United States designated the Islamic Revolutionary Guard Corps as a terrorist organization in 2019.
In June, the U.S. Justice Department charged Iraqi national Mohammad Baqer al-Saadi with plotting about 20 attacks against Jewish institutions in Europe and North America as part of an Iranian retaliation campaign.
According to MI5 Director General Sir Ken McCallum, “the UK Security Service and police tackled 20 potentially lethal, Iran-backed plots aimed at individuals based in the United Kingdom.”
Alan Mendoza, executive director of the Henry Jackson Society, a British political research center, told MBN that suspicion of a plot against a U.S.-used air base “would mark a step up for Iranian operations in Europe, which have usually targeted commercial, Iranian expatriate or Jewish community sites.”
“If proven to be linked,” he added, “this would reflect a mooted change in tactics by the regime in the summer where it warned that such bases were legitimate targets for its operations.”
According to the French domestic intelligence service DGSI, “the Iranian services have adapted their modus operandi and now more systematically prefer to use people from criminal circles” to carry out their attacks abroad.
Clara Broekaert, a research analyst at the Soufan Center, a New York-based research organization focused on terrorism and violent extremism, told MBN that Iran has long relied on “so-called disposable agents” or temporary operatives, predating the Iran war. She cited the use of the criminal Foxtrot gang in Sweden to carry out operations on Iran’s behalf.
But she said the current plot is also consistent with “Russia’s hybrid playbook in Europe, which likewise seeks to wreak havoc using disposable agents.”
In June 2018, French, German and Belgian authorities foiled a plot to bomb a gathering of the Iranian opposition near Paris. Among those charged were an Iranian couple, Assadollah Assadi and his wife, Nasima Naami. Belgian authorities found explosives in their car and subsequent investigations revealed their links to Iranian intelligence.
An interactive map published by the Washington Institute in 2024 points to a notable increase in Iranian activity in Europe, including the recruitment of criminals.
Broekaert noted that “while the operations, tactics, and targets chosen all appear to indicate an Iranian or Iran-backed militia group, layers of obfuscation are often used through intermediaries.” Some of those involved, she said, are driven by financial gain and may believe they are participating in ordinary criminal activity rather than carrying out terrorist operations on behalf of the Iranian regime.
Adapted and translated from the original Arabic.
