Six Iraqis and a German were arrested under anti-terrorism laws today outside an air force base in the east of England used by US forces, British police said.
Six members of the group were found hidden inside a civilian lorry outside the Lakenheath airbase.
Police said the group were believed to have entered Britain illegally earlier on Wednesday and had been arrested under immigration laws.
The stowaways were discovered because noises were heard from inside the vehicle, a police spokeswoman said.
Because of the circumstances surrounding their discovery all seven men were additionally detained under the Terrorism Act 2000, she added.
A spokeswoman for the Lakenheath base, which is home to units of the United States air force, said: I don't think they knew where they were.
They were locked in a compartment under a lorry and our security became aware of their presence because they were banging.
When asked if they had any connection with the current situation in the United States following the September 11 attacks, the spokeswoman said: I don't believe at the moment they have any connection.