Seven men have been arrested on suspicion of the commission, preparation or instigation of terrorism this week, after firearms were found hidden inside a car, West Midlands police said on Friday.

News of the West Midlands arrests comes a day after a separate operation in London, in which six people were arrested on suspicion of terrorism, and after a fake cigarette sparked a terror scare on a major motorway.

The firearms, offensive weapons and other material were found hidden inside a vehicle after police stopped it in a routine check and impounded it on suspicion of having no insurance.

The car was pulled over on the M1 in South Yorkshire on June 30 and the men were later detained on Tuesday, Wednesday and Thursday in West Midlands and West Yorkshire.

Detective Chief Superintendent Kenny Bell, the head of the West Midlands counter terrorism unit that is leading the investigation, 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.”

A spokesperson for David Cameron, prime minister, said there was no sense of alarm at the arrests coming three weeks before the start of the Olympic games.

“We have been looking at the issue of security at the Olympics for some time and we have robust plans in place,” he said.

The police are continuing with their inquiries and have been granted permission to detain the three men arrested on Tuesday until next Tuesday morning. For the other suspects, they have a further 48 hours before they need to charge, release or apply for a warrant of further detention.

The six arrests in the London boroughs of Ealing and Newham on Thursday were part of a pre-planned, intelligence-led operation and not linked to the Olympics, the Metropolitan Police stressed.

One of the men arrested in London served as a Police Community Support Officer with the Metropolitan Police between May 2007 and September 2009. The police said he had not been deployed in a specialist or sensitive role.

Get alerts on Terrorism when a new story is published

Copyright The Financial Times Limited 2018. All rights reserved.

Follow the topics in this article