File picture: Britain will deploy an extra 1 200 troops to the London Olympics, the government announced Tuesday, following a last-minute recruitment meltdown at the Games' private security contractor G4S. REUTERS/Darren Staples

London - Seven men have been arrested on suspicion of terrorist offenses in Britain after a routine vehicle search turned up firearms and weapons, police said Friday.

The arrests, which took place earlier this week, were announced one day after officers in London detained six other terror suspects using stun guns and smoke grenades in an early-morning swoop on a home close to London's Olympic Park.

West Midlands Police said Friday a car was stopped on the M1 motorway in South Yorkshire on June 30 and impounded for not having insurance. It said “firearms, offensive weapons and other material” were later found hidden in it, which prompted police to trace and arrest the driver, passenger and other suspects.

Police said three of the men were arrested Tuesday, three on Wednesday and one on Thursday. Six of them are in their twenties and from the West Midlands area of England, while one is from West Yorkshire.

The men have been arrested on suspicion of preparing or instigating acts of terrorism. They were being questioned by officers and their residences were searched.

The items found in the vehicle were undergoing forensic testing.

Britain's terror level is currently ranked as substantial - the third highest point on a five-point scale - and means an attack is a strong possibility. Intelligence officials say there has been an expected increase in chatter among extremist groups ahead of the Olympics, but there are still no specific or credible threats targeting the games.

The London Olympics begin July 27 and end August 13. - Sapa-AP