Seven men have been arrested by police in anti-terror raids, after they were stopped on the M1 in South Yorkshire.
Six suspects in their 20s from the West Midlands and one from West Yorkshire aged 43 were detained over three days.
The arrests followed a routine stop of a vehicle by police. The location of the arrest has not been revealed.
West Midlands police say The car was impounded on suspicion of having no insurance. Firearms, offensive weapons and other material were later found hidden inside, prompting police to take action to trace and arrest the driver, passenger and others suspected of being involved.
The items from the vehicle are currently undergoing forensic analysis and searches are or have been carried out at the addresses of those in custody.
West Midlands Counter Terrorism Unit is leading the investigation. Head of the unit, Detective Chief Superintendent Kenny Bell, said: “As soon as the items were discovered in the impounded vehicle, our priority was to protect the public by pursuing and arresting those we believed to be involved.
“Our enquiries are ongoing.”
It is understood that the arrests are not being linked to the London 2012 Olympics which take place later this month.
Six of the men arrested are from the Sparkhill, Moseley, Alum Rock and Smethwick areas of the West Midlands with a man from Kirklees, in West Yorkshire.