(Reuters) LONDON, Oct. 8 — British counter-terrorism officers are investigating the arrests of two Latvian nationals who were detained near a Royal Air Force facility in Cambridgeshire early Thursday, police said.

Authorities said there is currently no evidence connecting the arrests to an alleged plan targeting another British military installation in western England. That base, RAF Fairford, had been used by U.S. forces to conduct bombing operations against Iran.

The two men came to police attention after Ministry of Defence Police discovered an unattended vehicle during a security patrol at RAF Molesworth, roughly 100 kilometers (62 miles) north of London. Officers subsequently identified a small opening in the base’s perimeter fence and arrested the men, aged 32 and 36, inside the military facility.

The pair were initially detained on suspicion of trespassing at a prohibited location and causing criminal damage. Police later arrested them again under the National Security Act 2023 on suspicion of “entering a prohibited place for a purpose prejudicial to the UK”.

The arrests come after several men were detained last month in connection with an alleged plan to attack RAF Fairford, located about 145 kilometers (90 miles) west of London. The British government has associated that suspected plot with Iran, although Tehran has rejected any involvement.

The latest incident has heightened scrutiny of security at British military installations, particularly facilities used by U.S. forces. U.S. officials said Monday that concerns about an Iran-linked threat had led Washington to withdraw its bombers from Fairford.

“We’re ⁠very aware of the recent heightened interest and concern around military sites, but at this stage there is nothing to suggest ​this incident is connected to the events at RAF Fairford ​last week,” Helen Flanagan, head of Counter Terrorism Policing London, said in a statement on Thursday.

As part of the investigation into Thursday’s arrests, police said officers were conducting searches at two properties in the Peterborough area.

The abandoned vehicle found near the base was also examined by bomb disposal specialists after being recovered by police. Officers said the inspection found nothing suspicious or concerning.