The US Embassy in London urged US citizens living in the UK to remain vigilant, warning that the risk of terrorist attacks was high.
In a written statement, the embassy said an attempt had been made the previous day to carry out a terrorist attack at Fairford Air Base in the UK, which is used by the US armed forces. The statement also recalled that several homes had been evacuated in a village near the base.
85 homes evacuated near Fairford Air Base
Eighty-five homes were evacuated in the village of Welford in Gloucestershire on September 27 after three suspicious vehicles were identified near Fairford Air Base.

Five people in the vehicles were detained, and bomb-disposal teams from the British Army were sent to the area. While British authorities investigate the possibility of a terrorist attack targeting the base, they are also assessing claims that Iran played a role in the incident.
Security advice for US citizens
The embassy said buildings, organizations and gatherings linked to the US could carry a higher risk. Citizens were urged to remain aware of their surroundings, follow warnings from local authorities and review their personal security plans.

The warning also advised informing relatives about security measures, monitoring statements from local media and security agencies, and following the instructions of emergency response teams. The statement also recommended enrolling in the US Smart Traveler Enrollment Program.
Different views on the use of Fairford Air Base
Fairford Air Base has been used by warplanes belonging to the US armed forces since Israel and the US began attacks against Iran on February 28.
The UK says the base is being used by the US for defensive purposes. Research organizations such as Chatham House and independent analysts, however, argue that Fairford Air Base is being used to launch attacks.