The United Kingdom has “strong indications” that Iran was involved in the incident in which five men were arrested near a US-run military air base in England late at night, Prime Minister Andy Burnham said on Wednesday. Burnham said UK and US officials are carrying out a “complex and serious” investigation into how and why five men and three vans were near the perimeter of RAF Fairford, a base that has been used by US bombers attacking Iran during this year’s war. Five British men in their 20s were arrested on Sunday on suspicion of explosives offenses and planning an act of terrorism, before being released on bail a day later. Police say they found a quantity of accelerant (gasoline) in the trucks, but no explosives. Burnham did not provide details about what the suspects were planning or why the UK believes Iran was involved. He said he would “update people further in due course”. “There are strong indications that Iran played a role in what happened over the weekend at RAF Fairford, but of course it remains an ongoing, complex and serious police investigation,” Burnham told the BBC in one of a series of interviews with British broadcasters. “And, of course, we are working closely with our colleagues in the United States of America.” 2:04 Questions raised in UK terrorism inquiry. Iran has denied involvement in the incident. It has previously said it considers any base used to attack its territory as a legitimate target. Get daily national news Get daily Canadian news delivered to your inbox so you never miss the day’s top stories. The base 160 kilometers (100 miles) west of London has been used by American bombers during decades of conflicts in the Middle East, including this year’s war with Iran. Senior US officials have criticized the decision to grant bail to the suspects; President Donald Trump said, “I wouldn’t have done that,” and Secretary of State Marco Rubio said many people were “disturbed” by the move. Burnham said authorities have the investigation under “the strongest and closest control,” and that British officials had been “talking to their counterparts in the United States all week to explain what’s happening here, how things are being done.” “I have full confidence in the way the British security services are handling this,” he told the BBC. He said one line of inquiry is whether the suspected crimes were committed by “representatives or individuals, whether knowingly or unknowingly, working on behalf of a foreign state.” The arrests came at a time of heightened tensions over the threat from hostile states, with British security services saying Russia and Iran have used proxies to commit crimes on UK soil. British officials have said the number of national security cases involving activities by hostile states, including Iran, rose by 50 percent in the six months to December 2025. UK officials also say Iran-linked proxies have been behind a series of arsons and other attacks in the UK and other countries, many of them targeting the Jewish community and intended to sow fear. They have previously warned that Tehran could expand its targets in the UK if conflicts in the Middle East continue. © 2026 The Canadian Press