Five UK nationals arrested after three suspicious vehicles were reported travelling towards RAF Fairford are now being held on suspicion of preparing a terrorist act as well as offences under the Explosives Act, UK Defence Journal understands.

The men were arrested in Whelford early on Sunday morning after Gloucestershire Constabulary received a call at around 12.45am concerning three vehicles travelling towards the US-operated airbase. Armed officers responded and detained all five, while an Army explosive ordnance disposal team was deployed to examine the vehicles and a 400-metre cordon was established around the scene.

Counter Terror Police say that specially trained Counter Terrorism Policing investigators examined the scene overnight and carried out further activity which has generated multiple new lines of enquiry. Significant numbers of resources, including military assets, remain deployed at the location while investigators continue their work.

We understand that the five men are being detained on suspicion of offences under the Explosives Act and preparation of a terrorist act contrary to Section 5 of the Terrorism Act. They are:

• A 24-year-old man, resident in the London Borough of Camden, UK national.
• A 24-year-old man, resident in the London Borough of Westminster, UK national.
• A 25-year-old man, resident in the London Borough of Westminster, UK national.
• A 23-year-old man, resident in the London Borough of Westminster, UK national.
• A 24-year-old man, resident in the London Borough of Willesden, UK national.

The men are being held under the Police and Criminal Evidence Act and that a custody extension has been secured until later today.

Counter Terrorism Policing said: “At this time, we are working to establish the full circumstances of the activity of those arrested, their knowledge and any motivation behind this incident.”

We understand that a cordon remains in place at the location and is due to be reviewed later today, while substantial policing resources and military assets remain at the scene.

Counter Terrorism Policing said: “The nature of this investigation means significant numbers of resources, including military assets, remain deployed at the location, and we thank the public for their ongoing support. We are working hard to minimise disruption to local communities, but ask for their patience, as our work continues at the scene.”

The force added: “Specially trained CTP investigators have been examining the scene overnight and have been carrying out a range of activity, which have led to multiple new lines of enquiry.”

Counter Terrorism Policing Senior National Coordinator Deputy Assistant Commissioner Vicki Evans said: “This is a hugely complex and large-scale operation, involving local and national policing, the MOD, and local agencies, who are working together to progress the investigation and support for the community.

“I know this has been incredibly disruptive for local people, but I’d like to reassure them that our activity is in the interest of national security, but most importantly in the interest of their own safety.

“I’d also like to thank the emergency services for their response, including the armed officers who first attended the scene, not knowing what they may face.

“I am very aware of the levels of speculation about the motivation behind this incident, and the geopolitical questions that are being raised. However, I ask that at this time, Counter Terrorism Policing are given the space to work carefully and clearly.”

The arrests followed the initial Gloucestershire Constabulary response on Sunday, when police said around 85 households had been advised to evacuate as a precaution while the vehicles were examined. A nearby leisure centre was opened for residents unable to stay with family or friends.

In its first detailed statement, Gloucestershire Constabulary said: “At around 12.45am today, Sunday the 27th of September, police received a call relating to three suspicious vehicles travelling towards RAF Fairford. Armed officers responded, and subsequently arrested five men in the Whelford area on suspicion of committing offences under the Explosives Act. The men were taken into custody, where they remain.”

The force added: “A 400 metre cordon has been put in place around the vehicles while the Army’s explosive ordnance disposal unit examine them. As a precaution, around 85 households have been advised to evacuate while these examinations take place. A nearby leisure centre has been opened for those who are unable to stay with family or friends.”

Police had already confirmed on Sunday that counter-terrorism officers were involved. Gloucestershire Constabulary said: “The emergency services have well-rehearsed plans for dealing with major incidents such as this. Work to establish the full nature of this incident is ongoing, and we are in constant communication with our partners, both locally and nationally. In particular, we are working closely with our partners in counter-terrorism policing.”

UKDJ understands that investigators are continuing to establish the full circumstances surrounding the activity of those arrested, including their knowledge and any motivation. Counter Terrorism Policing has not publicly attributed the incident to any organisation, ideology or state.