US military aircraft leave second UK airbase amid heightened security concerns

At least 10 United States Air Force refuelling aircraft have departed RAF Mildenhall in Suffolk, marking the second major movement of American military aircraft away from a UK airbase in recent weeks.

Flight-tracking data reviewed by BBC Verify shows that the aircraft left RAF Mildenhall on Monday, with some heading to other US military installations across Europe and one travelling to Prestwick Airport in Ayrshire, Scotland.

The departures come amid growing security concerns surrounding potential Iranian threats against US military personnel and facilities overseas.

While the precise reason for the aircraft movements has not been officially confirmed, The Wall Street Journal reported that the relocation was connected to a threat from Iran. The BBC has not independently verified that claim.

US refuelling aircraft relocate across Europe

Using publicly available flight-tracking information from Flightradar24, BBC Verify identified multiple USAF KC-135 Stratotanker aircraft departing RAF Mildenhall throughout Monday.

Two aircraft initially travelled towards US bases in Germany and Italy. One subsequently returned to Mildenhall before heading east again and landing at Spangdahlem Air Base in Germany.

The other aircraft, after flying circuits over Aviano Air Base in Italy, also continued to Spangdahlem.

A further eight KC-135 aircraft departed Mildenhall later in the day.

Another US military aircraft landed at Prestwick Airport in Scotland. It is associated with the Nebraska Air National Guard and may have been making a routine stop before returning to its American base.

The US Air Force has said that its aircraft regularly rotate between installations and operating locations for various reasons, including training and operational requirements.

A spokesperson added that American aircraft are hosted in accordance with existing access, basing and overflight agreements with allied countries. The service declined to provide further details about individual aircraft movements, citing operational security.

RAF Mildenhall and its strategic importance

RAF Mildenhall is an important US military installation in Suffolk, approximately 80 miles (130km) north of London.

Around 3,000 military personnel are stationed at the base, which is primarily used for aircraft refuelling and maintenance operations.

It has also served as a staging location for aircraft and military equipment heading towards the Middle East.

US aerial refuelling tankers have previously been forward deployed to the region during military operations involving Iran.

The base has also been used by aircraft transporting American presidents, including Donald Trump, who passed through Mildenhall following the NATO summit in Ankara in July.

Despite Monday's departures, the BBC reported relatively little aircraft activity at the installation, with no obvious additional security measures visible around the base.

Second UK base affected following RAF Fairford incident

The latest aircraft movements follow the withdrawal of American bombers from RAF Fairford in Gloucestershire in September.

That decision came after a security incident involving three suspicious vans near the base, which resulted in a major incident being declared.

The United States subsequently withdrew its bombers from Fairford and returned them to America.

Prime Minister Andy Burnham previously told the BBC there were strong indications that Iran had played a role in the incident. Tehran has denied involvement.

Two British nationals appeared in court in October in connection with an alleged Iran-linked plot, while several other individuals have been arrested as part of the counter-terrorism investigation.

Iran has previously warned that British military bases used by the United States for strikes against Iranian targets could be considered legitimate targets.

UK Government insists bases remain safe

The latest movements have prompted questions about the security of American military installations operating from British territory.

Downing Street has sought to reassure the public, stressing that the protection of military bases in the UK and overseas remains a government priority.

The Prime Minister's official spokesperson said:

"The protection of our bases, both in the UK and across the world, is a top priority. We work closely with the police and our allies to protect our sites."

Education Secretary Lucy Powell, speaking to BBC Breakfast, said she could not comment on ongoing operational matters but emphasised that the Government takes the security and safety of military bases extremely seriously.

She added that the authorities would act on security intelligence whenever necessary.

Meanwhile, former UK National Security Adviser Lord Ricketts highlighted the vulnerability of large military aircraft and the installations that accommodate them.

He explained that airbases have extensive perimeters and that large refuelling aircraft could represent significant targets, suggesting that the movements may partly reflect an abundance of caution.

Wider tensions between Washington and Tehran

The developments come against a backdrop of continuing tensions between the United States and Iran.

US Secretary of State Marco Rubio was questioned on Monday about Iranian threats against American diplomats overseas.

He said the United States had responded by moving personnel away from potential threats, explaining that the safety of American personnel and their families abroad remained a priority.

Rubio added that whenever intelligence identifies a potential threat above a certain threshold, the US government will take appropriate action.

Although Washington has not officially linked the Mildenhall aircraft movements to a specific Iranian threat, the timing of the departures and the earlier withdrawal from RAF Fairford have raised wider questions about the security environment surrounding American military operations in Britain.

What happens next?

For now, neither the US military nor the British Government has confirmed that the aircraft movements represent an emergency evacuation or a permanent change to American operations in the UK.

The US Air Force maintains that aircraft regularly rotate between installations for operational and training purposes.

However, the departure of aircraft from two strategically important British bases within a relatively short period has placed renewed attention on the security arrangements surrounding US military facilities in the United Kingdom.

With investigations into the RAF Fairford incident continuing and tensions involving Iran remaining a concern, further developments will be closely watched by both governments.