Counter-terror police are leading the investigation into a major incident near RAF Fairford - watch live footage of wheeled robots approaching vans at the scene above
Several men have been arrested on suspicion of offences under the Explosives Act, Gloucestershire police say - the force is expected to give a news conference shortly
Residents in the village of Whelford, near the base, have been evacuated - what we know so far
"It all happened very quickly. We just packed our stuff up and came here," says one of the evacuated residents
RAF Fairford has long been used as a forward operating location by the US military, as the country's Air Force say they "remain vigilant" following the incident
The context for this is troubling and comes amid a rising number of incidents across Europe of what's termed "hybrid warfare", Frank Gardner writes
Helicopter footage taken near RAF Fairford has shown a wheeled robot operating near three parked white vans.
Earlier, Gloucestershire Police said the Army's specialist explosive ordnance disposal team is examining a number of vehicles in the village of Whelford.
The force has not confirmed which vehicles were being examined, or mentioned the use of a robot.
A resident evacuated from his home near RAF Fairford in the early hours of Sunday says three "unusual vans" appeared in the area overnight.
Julian Tubsbery claims footage recorded by doorbell cameras in the area since the evacuations has shown "some robots looking in the back of these vans".
He says: "There were these three vans that arrived in the middle of the village and a resident reported them to the police straight away."
Police have not made any mention of vans or the use of robots.
Annabelle Martin
Reporter
Jason, an evacuated resident who has been at the leisure centre since about 7am, told the BBC that he was first made aware of the incident after seeing "some messages on the village group" last night.
Jason says he heard the helicopter but went to bed as normal before being woken by police officers.
"It all happened very quickly. We just packed our stuff up and came here."
He says the police described the situation as a "major incident" and had given residents "basic updates".
Jason says he had to bring his ill cat with him, that was supposed to be heading to the vets today.
He says: "It's been a bit full on. A bit eventful."
We're now seeing live aerial pictures from near RAF Fairford in Gloucestershire where there is a heavy police presence following the arrest of several men on suspicion of offences under the Explosives Act.
You can watch live at the top of the page.
Image source, Getty ImagesHome Secretary Shabana Mahmood says emergency crews responding to the incident near RAF Fairfod believe it is now "contained".
"I would like to thank the emergency services for their swift response to the major incident in Gloucestershire this morning and their reassurance that they believe the incident is contained," she writes on X.
"Whilst investigations are ongoing it would be inappropriate to comment further."
Sammy Jenkins
BBC News, Live page reporter
Image source, REUTERS/Toby ShepheardLocated on the border of Gloucestershire and Wiltshire, RAF Fairford has long been used as a forward operating location by the US Air Force (USAF).
Its history with the US Air Force goes back decades, with the site occupied by USAF Strategic Air Command during the Cold War and later the first Gulf War in 1991.
B-52 bombers were also deployed by USAF from the site on raids to Iraq in 2003.
It was most recently used on 1 March though after former prime minister Sir Keir Starmer granted permission for "defensive" US action against Iranian missile sites from the base.
US heavy bombers soon started taking off from RAF Fairford in what the Ministry of Defence (MOD) described as "defensive missions to destroy Iran's missile capabilities".
The move came after after the US and Israel began attacking Iran on Saturday 28 February.
Chris Partridge
BBC News weapons analyst
Image source, Getty ImagesRAF Fairford saw large amounts of activity earlier this year as US Air Force heavy bombers departed to strike targets in Iran.
I saw B-52 bombers from the Cold War era departing from the airbase loaded up with AGM-158 air launched cruise missiles for stand-off precision attacks.
These weapons have a range of some 500 miles, giving US military planners the ability to strike high-value, protected targets at distance.
In additional I also saw newer B-1b bombers loaded up with GBU-31(v) 3/b JDAM free-fall precision guided bombs - these types the penetrating "bunker busting" variety. The bombs would likely have been selectively used against hardened targets or underground weapons' stores.
Each bombing mission, depending on the location of the target, would likely have taken about 12 to 15 hours in total there and back, with air-to-air refuelling both ways.
The bombers would also have been supported by fighter jets closer to the theatre - such as F/A-18 Super Hornets and F-16 Vipers.
These jets would carry out Suppression/Destruction of Enemy Air Defences (SEAD/DEAD) roles to guard against surface to air missile threats and radar-guided anti-aircraft fire from the ground.
Leigh Boobyer
Live page reporter
Gloucestershire Police has confirmed a statement will be read to the media at 12:45 BST in relation to the major incident.
It will be delivered by a senior officer who will not be answering questions after the briefing.
Image source, Getty ImagesRAF Lakenheath is home to the US Air Forces' 48th Fighter Wing
The US Department of Defence has raised the threat level at RAF Lakenheath in Suffolk - which hosts the US Air Force's 48th Fighter Wing - following the incident near RAF Fairford.
RAF Lakenheath confirmed that the base is on Charlie alert, the second-highest threat level that can be issued by the US DoD.
It follows reports that RAF Fairford has been raised to the highest threat level, Delta
The US government says threat level Charlie applies when "an incident occurs or intelligence is received indicating some form of terrorist action targeting personnel or facilities is likely”.
While it says Delta applies "in the immediate area where a terrorist attack has occurred or when intelligence has been received that terrorist action against a specific location or person is imminent".
Nick Johnson
BBC News
Image source, PA MediaI spent a number of days around RAF Fairford as US bombers and military equipment arrived at the beginning of March, following US strikes on Iran.
Impressive military machinery was taking off and landing with frequency - providing an accessible spectacle for aviation enthusiasts.
I was struck by how close the public could get to the large perimeter fence - just beyond which the US Air Force's B-1 bombers were positioned.
While police officers made occasional security checks and ensured parked cars were not blocking roads or homes, there were many hundreds of people who were easily able to gather at the perimeter fences.
We do not yet know the nature of this incident but it may prompt a rethink regarding how close cars and people are able to get to the airfield itself.
Jack Grey
Live reporter
Image source, PA MediaArrests have been made and a major incident declared following an incident near RAF Fairford in Gloucestershire.
Here's what we know:
What we don't yet know:
Sammy Jenkins
BBC News, Live page reporter
The Royal Air Force Station is located in the Cotswolds about four miles (6.4km) south of the town of Fairford, which sits along the River Coln.
The area is typically quiet but about 170,000 people descend on the RAF site every July for the Royal International Air Tattoo, the largest military show in the world.
The event was cancelled this year due to the conflict in the Middle East.
Annabelle Martin
Reporter
I'm at the the leisure centre where residents have been placed after being ordered to leave their homes during the middle of the night.
Families are gathered in a café area, anxiously checking their phones and asking for updates. About 30 people are here, including children and elderly people, with some still in their pyjamas.
Leigh Boobyer
Live page reporter
Prime Minister Andy Burnham is receiving updates on the incident near RAF Fairford.
A government spokesperson said: “We are grateful to the emergency services, who have acted quickly to detain several suspects and put measures in place to keep the community safe.
“It would be inappropriate to comment further whilst investigations are ongoing.”
Alastair McKee
Reporting from the scene
I'm at the scene near RAF Fairford, where cyclists and drivers are being turned around by police near the cordon.
The cordon is a substantial way out of the village, beyond the sight of homes.
I'm stood by the RAF base, and I can see through the fence the B-1 Lancer bombers used by the USAF.
Police are in full gear and armed.
Frank Gardner
Security correspondent
Whitehall officials say the investigation into the incident at RAF Fairford is being led by counter-terror police. The BBC understands that it was not intelligence-led.
Image source, PA MediaDefence Secretary Wes Streeting has thanked emergency crews for their "swift" response to the incident near RAF Fairford.
"We can be reassured that this is being dealt with and it is exactly why our emergency response teams and Armed Forces are on standby 24/7," he writes on X.
Leigh Boobyer
Live page reporter
Speaking to the BBC, Cotswold district councillor Tristan Wilkinson urged people to "remain calm".
"It's new so we need to keep speculation to a bare minimum.
"All I ask is people stay away from the area. This is a serious incident," he added.
Image source, ReutersArmed police are at the scene
Describing the scenes near RAF Fairford as "worrying", South Cotswolds MP Roz Savage said on X: “I have contacted the police for further updates and I’ve been told that it is believed the incident is contained.
“I would like to thank them for the work they are currently doing."
A spokesperson for the US Air Force said its personnel based at RAF Fairford "remain vigilant".
They added that while they were aware of the current situation at Fairford, they would not discuss specific force protection measures.
"The 501st Combat Support Wing and our fellow UK-based Wings remain vigilant and will take appropriate actions to ensure the safety and security of our US service members, civilians, contractors, and their families," the spokesperson said.
"We constantly assess a variety of factors that determine what measures we institute or modify to protect our installations, our people and their families."
Britain said in July its armed forces were ready to protect the country from any attack after Iran's Revolutionary Guards issued a warning not to allow US bombers to fly from Fairford.
The Fairford site has been used since February to launch operations against Iran during the Middle East conflict.
