Defence Secretary Wes Streeting says the investigation into the events near RAF Fairford is now "well under way".

He tells Radio 5 Live Breakfast it was difficult for him to comment further due to the live investigation.

Asked whether the arrests near the RAF base were based solely on a random tip-off from a member of the public or a more sophisticated surveillance operation, Streeting says: "Firstly I want to pay tribute to that member of the public for her vigilance, she’s done exactly what we would hope a member of the public would do in the situation she found herself in.

"She will of course only have had a partial view, and I don’t want to go beyond and stray into kind of operational and security detail at this stage.

"But I think we can be proud of the work that our police, counterterrorism police and security services do to keep us safe."

Streeting adds that "we have very robust tried and tested methods for protecting all of our bases around the UK and around the world".

Edward Rowe
Reporting from the scene

Despite the continuing police presence around the airbase this morning, the overwhelming sense here is of a peaceful rural location.

This might be an international incident generating commentary from both sides of the Atlantic, but nobody told the birds.

Since I arrived here at 06:00 BST this morning, parked next to a couple of farmers fields, it’s felt like a classic English countryside scene. A misty autumnal morning filled with birdsong and the smell of manure.

It couldn’t feel further from the corridors of power on both sides of the Atlantic where it is being discussed. The flashing lights of the police cordon are the only signs of the severity of the situation.

We're expecting Defence Secretary Wes Streeting to appear on BBC Breakfast at around 07:30 BST and to be speaking to Radio 4's Today programme at 08:10 BST.

You can follow BBC Radio 4 and BBC Breakfast TV in our live streams at the top of the page.

We'll be bringing you the key lines here.

Bea Swallow
Live page reporter

The farmer who alerted police to the suspicious activity near RAF Fairford believes "someone dropped the ball" by allowing the suspects and their vehicles to get so close to residential properties.

She told the BBC the three white vans were parked within metres of neighbours' homes - with those sleeping inside unaware of the potential danger.

"We need to be able to trust that the relevant authorities will take appropriate steps to monitor and manage threats to the communities who live and work in close proximity to the base," she said.

"It shouldn’t be necessary for someone like me to alert RAF Fairford of the presence of three large suspicious vehicles and a group of masked men."

The farmer, who chose to remain anonymous, said the incident left her with the impression that authorities were "hyper focused and vigilant" on protecting the base, but "had absolutely no regard for our village".

Edward Rowe
Reporting from the scene

I’ve just arrived at the cordon and it’s all quiet with one police car on the scene, its lights illuminating the gloom, not letting anyone through.

It means the people evacuated yesterday from the 85 homes in the village of Whelford are still waiting to return home.

Police have told me this morning only army personnel and emergency services have been let through, while the three vans that explosives experts have been examining remain further up the road.

Emergency service personnel are gathering at a local football club, with lots of police cars and fire engines visible there.

Meanwhile, activity at RAF Fairford seems to be continuing. I heard a plane as I arrived.

The farmer who called 999 has been speaking to the BBC's Today programme.

You can listen to the full interview on the programme on Radio 4 at 07:09 BST - press listen live at the top of the page.

Police are still questioning five men who were arrested close to the base - which has been used by the US Air Force to launch attacks against Iran - this morning.

A sizeable operation was launched in the early hours of Sunday morning, raising important questions about the UK's national security after President Donald Trump claimed US and UK authorities had been working together to monitor a potential plot to attack the base.

But despite that, it appears the arrests were made after a tip-off from a member of the public - a farmer who called police after noticing "a large group of hooded and masked men" lingering near the treeline.

Image source, Reuters

"When they saw me they ran ahead of me - some into the field and some towards the neighbouring village," she said. "I then realised that something highly unusual was taking place."

She said she immediately called the Ministry of Defence but the phone rang out, and her instincts told her to call 999.

"Within 10 minutes the village was full of armed police. I think it was pure luck that I arrived in the village at a similar time to the vans," she added.

"I am absolutely staggered that it was left to me as a member of the public to see and report this. I believe that my 999 call foiled whatever plans they had."

Nick Johnson
Reporting from the scene

There remains a very reactive police presence around RAF Fairford this morning.

We and other journalists have been asked to move location a number of times - and officers appear to have set up an ad hoc checkpoint for cars trying to drive past the base.

Despite Gloucestershire Police saying the matter is “contained”, the cordon is yet to be lifted and there doesn’t appear to be a timetable for residents living nearby to be able to return to their homes.

Matty Edwards
Live page reporter

Welcome back to our live reporting on the major incident declared on Sunday at RAF Fairford in Gloucestershire.

Here's what we know so far about yesterday's incident.

• Five men are still in custody after being arrested on suspicion of preparing a terrorist act and explosive offences
• A major incident was declared near RAF Fairford where US Air Force planes operate from, after three "suspicious vehicles" were reported travelling towards the base at 00:45 BST on Sunday
• A local resident told the BBC she alerted the police to the activity near the base in the early hours of Sunday
• Residents from 85 homes evacuated from the nearby village of Whelford are yet to return home, while a 400m cordon remains in place around the area
• Gloucestershire Constabulary's temporary Chief Constable Maggie Blyth said on Sunday evening she believed the incident was "contained"
• Officers from Counter Terrorism Policing (CTP) are now leading the investigation into the incident, but the BBC understands the operation was not intelligence led

Freya Scott-Turner
Live reporter

Image source, PA Media

A quiet corner of Gloucestershire found itself at the centre of the headlines today, after police declared a major incident near RAF Fairford.

The alarm was sounded at around 00:45 BST, as "three suspicious vehicles" were seen travelling towards the base.

Five men have been arrested on suspicion of preparation of a terrorist act and explosive offences.

Fairford is used by the US Air Force, which has - since March - been launching attacks against Iran from its runway.

The investigation is now in the hands of Counter Terror Police, who have said its investigation is in the "early stages".

UK Prime Minister Andy Burnham has urged "not to speculate while the authorities establish the full facts". And we also heard from US President Donald Trump, who told reporters that the accused were "looking to do big damage to our fort".

As of Sunday evening, the cordon remains in place, and more than 80 households are unable to return home while investigations into the vehicles continue.

We're ending our live coverage now, but you can keep up-to-date with the latest on this in our news story.

James Landale
Diplomatic correspondent

RAF Fairford is a slice of America in the heart of England; a forward operating base for the US Air Force since the Cold War.

Its two-mile runway is so long it was once an emergency backup for the US space shuttle programme.

Now it is a vital launchpad for the vast, lumbering bombers President Donald Trump uses to strike Iran, the only airbase with such capabilities available to the US in Europe.

And that – by definition – has long made it a potential target.

In July, Iran's foreign ministry accused the UK of being complicit in war crimes for allowing the US to use Fairford as a staging post for defensive strikes in its war against Tehran.

And it warned "any party that, in any manner, participates in military aggression against Iran will bear responsibility for the consequences and repercussions of its decision".

That was seen as an explicit threat.

Read more in James Landale's full analysis here

Image source, PA Media

Simon Jones
Reporting from Gloucestershire

A local resident who says she alerted the police to suspicious activity around the military base in the early hours of this morning says she called the MoD police initially, but nobody answered.

The woman - who doesn't want to be named - saw the three vans parked up and a group of men wearing masks.

She then called 999. She says security had been stepped up around the base in recent days, so she was surprised the men had not been noticed before.

The MoD declined to comment.

As we've been reporting, Counter Terrorism Police (CTP) are now leading the investigation into the major incident around RAF Fairford.

CTP is not a distinct agency or an independent police force. Rather, it's a policing network.

It's made up of 11 regional counter terrorism units and intelligence units that collaborate to prevent and investigate terrorism in the UK.

Its personnel belong to 43 police forces from across England and Wales, alongside the police services of Scotland and Northern Ireland.

But CTP is unified centrally and has a headquarters in London, hosted by the Metropolitan Police.

Image source, Getty Images

What should have been a quiet Sunday morning in a Gloucestershire village has been upended, as the Army and other emergency services were called to respond to a major incident near the RAF Fairford military base.

Here's how it's unfolded.

00:45 BST: Gloucestershire police says it received a call reporting "three suspicious vehicles" travelling towards RAF Fairford.

Around 07:00 BST: Residents in the village of Whelford - which is around two miles (3.2 km) from the base - describe being woken up by police, who told them to evacuate from their homes to a local leisure centre.

Shortly after 08:00 BST: Gloucestershire police says a "major incident" has been declared near RAF Fairford, and that several men have been arrested on suspicion of explosives offences.

Throughout the morning: A cordon remains in place in Whelford, while specialist teams - and a robot - are seen examining vehicles.

11:33 BST: Home Secretary Shabana Mahmood confirms the incident has been "contained".

14:15 BST: Authorities give an update, confirming Counter Terrorism Police is leading the investigation. They say that that five men remain in custody.

Shortly after: Counter Terror Police says it is "in the early stages" of its investigation, and "working closely" with partners "understand the circumstances of the incident".

16:18 BST: US President Donald Trump tells reporters that the men arrested near RAF Fairford on Sunday were "looking to do big damage". "We had them under investigation," he adds.

18:13 BST: Police in Gloucestershire provide an update, saying that they consider the matter contained. It is also confirmed that dozens of displaced households will not return to homes inside the cordon tonight, as counter-terror police continue to investigate.

Local authorities in Gloucestershire have just given an update about the incident near RAF Fairford.

Here's what we learned:

• Gloucestershire Constabulary's Temporary Chief Constable Maggie Blyth said a disposal unit continues to examine three vehicles near Whelford
• She says that counter terrorism police are now leading the investigation and will decide if the case should be declared a terrorism incident - no such decision has been made so far
• The temporary chief constable gave reassurance that the incident is now contained following "swift arrests". She added that Gloucestershire police had been preparing for an incident of this nature
• Blyth said around 85 households can expect to be away from their homes this evening - David Stanley, of Cotswold District Council, said the council will support any residents who need accommodation or have other needs

A bit more now from the press conference with authorities in Gloucestershire, which has concluded.

David Stanley of Cotswold District Council says they have been working with the affected residents to arrange accommodation. He notes that some people are staying with family and friends, and the others will have overnight accommodation found for them.

Asked again about the phone call, Blyth says the she wants to reassure communities that any call into the force is "always acted on".

She is then asked if a controlled explosion was carried out. The police chief says she can not comment.

Responding to a question about how long residents can expect to be away from their homes, Blyth says they will not be able to return home this evening and the situation is being monitored.

Stanley, of Cotswold District Council, adds that the council will be reviewing the situation in light of any updates over the next few hours and it will support any residents with any accommodation or other needs if that is necessary.

Blyth is next asked if they are looking for anybody additional. She says she can't go into detail but "can give reassurance that we believe the matter to be contained".

Blyth adds that they are "gathering and responding to local intelligence all the time".

As for the concerns local residents might have about being so close to a US military base, Blyth says they respond to raised matters "all the time" in collaboration with other agencies.

David Stanley of Cotswold District Council adds here that they are "completely aware" of residents concerns, and are working to address these on an "ongoing basis".

Blyth is asking by LBC if Gloucestershire police had been preparing for a major incident like this.

She says the force prepares for this sort of incident "all of the time" and is very well prepared.

She adds that this is a "normal response for us".

Blyth says that there were "swift arrests" but does not say how many officers were involved in the response.

Blyth is also asked if the RAF did not pick up the phone when a concerned resident called. She says that she can not go into the response overnight.