Fairford is not the only UK air base used by the United States Air Force.

Over in Suffolk in the East of England are Mildenhall and Lakenheath, where the state of alert has been increased by the US to "Charlie" - the second-highest alert level.

Charlie alert is usually an indication an incident has happened or intelligence suggests there could be a potential attack.

Lakenheath is home to fighter jets, while Mildenhall is mainly used as a base for refuelling tankers.

In his speech at the Labour Party conference on Monday, Defence Secretary Wes Streeting said he couldn't provide much further detail about the terror probe at RAF Fairford beyond what has already been reported.

Instead he praised the strength of the UK-US alliance.

"Our friendship with America is the closest alliance of any two nations on Earth, and we will always stand together against those who hate our freedom and those who wish us harm," he said.

"What we saw yesterday from our security services, our armed forces and our police was just a small glimpse of the extraordinary work they do every day."

Image source, Reuters

Over the past few days a large number of emergency personnel have been basing themselves at Fairford Town Football Club.

The scene there this morning is "very quiet", our photographer says.

Bea Swallow
Live page reporter

RAF Fairford is a military airfield located in the Gloucestershire Cotswolds, about four miles (6.4km) south of the town of Fairford.

It is owned by the UK's Ministry of Defence (MoD), but is operated on a day-to-day basis by the United States Air Force (USAF) under an agreement between the UK and US.

The site shares a long history with the American military, and has recently been used by US warplanes as a staging post for strikes on Iran due to its long runway, from which it can quickly deploy large bombers.

Historically, aircraft launched from the site have been involved in the Gulf War, the Kosovo War, and the Iraq War.

The rural area is typically quiet but about 170,000 people descend on the 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 war between the US, Israel and Iran.

Matty Edwards
Live page reporter

Here's some more from Whelford councillor Tristan Wilkinson, who has been speaking to BBC Radio Gloucestershire.

He is calling for RAF Fairford to communicate better and make it as easy as possible to report any concerns.

"The one thing I will be pressing the authorities for in the coming days is that we have a clear way of raising concerns, so that - god forbid if somebody sees some suspicious activity in the coming weeks - everyone knows the right number to call and that number will be answered quickly," he says.

Image source, Reuters

"We need to make sure the communities living next to these potential threats are well informed and involved in some of the decision making," he adds.

"I can understand why there isn't an ongoing dialogue with the base about their operational activity, but I do think there are things we could put in place that inform and reassure the local community about what is going on."

Wilkinson is also urging the wider community to show "tolerance" and "understanding" towards the evacuated residents as they deal with the disruption.

Matty Edwards
Live page reporter

It will take "a considerable amount of time" for life in the village of Whelford to return to normal, according to the local councillor for the area.

Councillor Tristan Wilkinson tells BBC Radio Gloucestershire that the mood among residents is a mixture of "confusion" and "weariness".

The vast majority of residents have now gone home, he says, but some who live near to the cordon around the white vans are subject to tighter restrictions.

"I don't think there's going to be anything normal about Whelford for quite a considerable amount of time," he says.

"Even when the police leave and they deem the area to be completely safe, as long as the conflict in the Middle East carries on, the people of Whelford and Kempsford are going to be living next to an operational base, so I think it's really important that the message of vigilance stays top of people's minds," he says.

"I think the mood is predominantly one of confusion, because obviously there are different stories emerging about what the nature of this was," he adds.

"People are really keen to understand what actually happened, who were these people and what was their intention."

He says after disruption and the small village becoming an international news story over the last two days "people just want to get on with their lives".

The cordon around the three vans has been in place since Sunday.

But some residents are beginning to enter and leave the cordon this morning on the western side.

Image source, PA Media

Yesterday Counter Terrorism Police gave more detail about the five men arrested near RAF Fairford on Sunday morning.

All five are UK nationals, it said: a 24-year-old from Camden, north London, three men aged 23, 24 and 25 from Westminster, and one aged 24 from Willesden, north-west London.

The head of UK Counter Terrorism Policing, assistant commissioner Laurence Taylor, said the men were released on bail under "stringent conditions" on Monday, but "absolutely remain under investigation as we explore multiple lines of inquiry".

He acknowledged speculation around the possibility of Iranian involvement, and said the force was keeping "an open mind in this investigation".

"But be assured, we are considering this from every possible angle, including that this may be actively committed by proxies or individuals either knowingly or unknowingly working on behalf of a foreign state," he said.

Iran's London embassy said it "categorically rejects and strongly condemns the recent unfounded and malicious speculations" of Iranian involvement.

Chris Phillips, the former head of the UK National Counter Terrorism Security Office tells BBC Radio 5 Live he does not believe police were fully aware of what was unfolding at RAF Fairford on Sunday.

He tells Naga Munchetty: "Police in this country don't allow terrorists to get hold of weapons and certainly they don't allow them to have van-fulls of explosives before they interdict, so I would have anticipated them having been arrested before that.

"Certainly historically we would have never allow that to happen. Historically they would have been stopped prior even to putting the explosives in any vehicle."

Naga asks: "So the intimation is they didn't know?"

Phillips responds: "I think so - I think that's probably the most likely scenario."

He adds that there are many possible explanations.

This story is only just beginningpublished at 08:10 BST

08:10 BST

Daniel Sandford
UK correspondent

Image source, Reuters

I think we are left reading the room because criminal proceedings are active, but one of the things we can say with some certainty is that there was some suspicion before the arrests on Sunday that that there might be some kind of plot to attack the base at RAF Fairford.

There were clear signs that security was being stepped up last week.

I think the question is now, given that Marco Rubio and Donald Trump are clearly hinting that this involved the hand of a foreign actor, what role did the men who were arrested in the early hours of Sunday play and to what extent were they aware of that?

Clearly the fact that they were released on bail yesterday shows there was not sufficient evidence at that point to hold them any further or to bring charges against them.

On the face of it, you have five men sitting in a village in three vans in the early hours of Sunday morning without any explosives, because that seems to have been the outcome of the tests done on the things found in the back of those vans.

We don't know what these men said to police in their interviews, but a key line of enquiry in the second phase of this investigation is whether there was some kind of controlling hand behind the activities and whether the people at the scene were really aware of they were involved in.

I think that's where this key phrase from the head of counter terrorism yesterday comes in, where he said his detectives are looking at this from "every possible angle", including that this activity might have been committed by individuals, knowingly or unknowingly working on behalf of a foreign state.

This is just the beginning of this investigation, not anywhere near the end.

The focus will be on trying to work out what led to those men being there, and if they were unknowingly caught up in something or whether they were there for perfectly innocent reasons.

That means means going through telephones, computers, searches at addresses - that is going to be the next stage of the investigation

Talking to military and police sources, I get the impression this is a story which is only just beginning - it is nowhere near being over.

A cordon is still in place around three vans which are being examined by counter-terrorism police.

While residents are being allowed back to their homes, there are still armed police stationed around RAF Fairford.

Image source, Reuters

Image source, Reuters

Image source, Reuters

Marie Lennon
Reporting from the scene

There is still a heavily guarded police cordon around the RAF base at Fairford.

The residents who live in the nearby village of Whelford have been told they can move home, but there is still hesitancy among them.

One local tells the BBC most have returned home, but police are telling them to stay inside and not take any photos.

"I haven’t gone home as I want to wait until I know more about what the hell happened, as it feels super dodge to me," she says.

Nick Johnson
Reporting from RAF Fairford

A cordon remains around the three vans which counter-terrorism police have been examining for possible explosive devices.

I am assuming that no viable explosives have yet been found.

The five men who were arrested on Sunday on suspicion of explosive and terrorism offences near the RAF Fairford military base have been released under investigation, subject to "stringent" bail conditions.

When people are detained under the terrorist act, they can be held for 14 days without charge.

The fact that these men were detained and then released on police bail after about 24 hours, suggests that police were pretty sure that other lines of inquiry needed to be followed.

Image source, EPA/Shutterstock

If you're just joining us, here's a recap of what we've learned over the past 48 hours as police investigate the incident at RAF Fairford.

• Counter Terrorism Policing (CTP) released five British men in their early 20s on bail on Monday after they were arrested on suspicion of committing offences under the Explosives Act
• The men remain under investigation and their release is "subject to stringent conditions on their movement and contact with others"

• On Sunday at about 00:45 BST, Gloucestershire Police received a call relating to three "suspicious vehicles" heading towards RAF Fairford, an airbase that has been used by the US to launch attacks against Iran

• Shortly after this call, at 01:36 BST, a local farmer says she called police about "a large group of hooded and masked men" close to the base
• While President Trump has said the suspects were "under view for a long time", the BBC understands the operation was not "intelligence-led"
• CTP said officers were exploring "multiple lines of inquiry", including whether proxies or individuals working on behalf of a foreign state were involved.
• Local residents have told the BBC about heightened security around the airbase in the days and hours leading up to the arrests
• A cordon remains in place near the base, while 85 households who were evacuated were told on Monday by Gloucestershire police that they could return home

• BBC Verify has looked at the "Fuel 2 You" vans found near RAF Fairford but found no evidence it is a genuine company

US Secretary of State Marco Rubio has told Fox News network's "Hannity" programme that it was clear a "foreign actor" had been involved.

Without providing evidence or giving further details, he told the TV show:"I have to be careful, there are some things I cannot say on the air for a lot of different reasons. Suffice it to say, that what happened, what almost happened, what could have happened, in the UK over the weekend, is a very serious situation.

"It’s one that clearly involves the hands of a foreign actor."

"I won’t get into great detail about that yet. I do want to thank the authorities in the United Kingdom who have been very co-operative and on top of it.

"I know a lot of people are disturbed by the news that some of these people have been released on bail, some of the people are being investigated. Obviously we’re engaging with them on all of that.

"But suffice it to say, beyond that I would argue that they’ve been very co-operative and very helpful, on something that’s a very serious incident."

Good morning, we are resuming our live coverage of the major incident at RAF Fairford.

We have a reporter at the scene as local residents are now able to return home, the day after the five men arrested in the early hours of Sunday morning were released under investigation.

Gabriela Pomeroy
Live reporter

Image source, Reuters

The five men who were arrested on Sunday on suspicion of explosive and terrorism offences near the RAF Fairford military base have been released on bail, UK counter-terrorism police said this afternoon.

The men - who are all British - remain under investigation, "as we explore multiple lines of inquiry, the head of counter-terrorism policing, Laurence Taylor,told reporters.

Police are exploring whether proxies or individuals working on behalf of a foreign state were involved, he said.

The release of the five men sits at odds with our being told this was a "major incident," the BBC's Security Correspondent Frank Gardner writes.

A large cordon remains in place near the base, while 85 households who were evacuated on Sunday have now been told by Gloucestershire Police that they can return home.

Many questions remain unanswered about the incident, including how President Trump's comments on the matter relate to the developments.

The US president said on Sunday: "We had them under investigation. They were looking to do big damage.”

After the five men were released on Monday, Trump weighed in again, saying he wouldn't have let them out on bail.

We are ending our live coverage now but you can read our news story here.

Christopher Mace
Live page reporter

Earlier we brought you a picture appearing to show an open and unguarded gate and barrier at RAF Fairford, reportedly taken on Thursday 24 September.

We sent the image to the United States Air Force this afternoon and they have now issued a response:

"For operational security reasons we will not discuss specific force protection measures.

"The 501st Combat Support Wing remains vigilant and will take appropriate actions to ensure the safety and security of our US service members, civilians, contractors, and their families across the European theater."

They added: "We constantly assess a variety of factors that determine what measures we institute or modify to protect our installations, our people and their families."

Bernd Debusmann Jr
White House reporter

As we've reported, President Trump was briefly asked about the incident at RAF Fairford.

His answers, however, did not provide much clarity - other than to make clear he was surprised and perhaps somewhat dismayed the five men arrested on Sunday have been released on bail, and that he views the co-operation with UK authorities as "very good".

While Trump said that Iran "might" be linked to the incident, he declined to provide any further details on what makes him believe that.

Since the US began striking Iran in late February, the White House and Trump have repeatedly described Iran's government as one that has been linked to terrorist attacks on US targets, stretching back to the founding of the Islamic Republic and bombings and kidnappings that took place in Lebanon in early 1980s.

Notably, there seems to be a disconnect between what Trump is saying and what British authorities are saying regarding the incident, with Trump saying that "we know everything" about the suspects and police in the UK stating that this was not an intelligence-led operation.

Image source, EPA

Speaking in the Oval Office, Trump says he wouldn't have let the five men arrested near RAF Fairford out on bail.

"I'm surprised they released them, I wouldn't have," he says.

"We know everything about them, we would not have released them."

He adds that the UK has been "very good" and has worked with the US "very closely".