HAMPSHIRE police are investigating a suspected explosive device, which was sent to an army recruitment office.
The device is one of seven discovered across the country in the last three days.
Prime Minister David Cameron chaired a meeting of the Government's Cobra emergencies committee to discuss the suspicious parcels, which sources said were ''crude'' in design but ''could have caused injury to others''.
Counter-terrorism police consider the packages to pose a ''low-level threat''.
The Hampshire package was found in Aldershot, yesterday.
Four parcels were discovered at Army careers offices in Oxford, Brighton, Canterbury and the Queensmere shopping centre in Slough today, counter-terrorism police officers said.
Two packets were found on Tuesday at the armed forces careers office in Reading, Berkshire, and the Army and RAF careers office in Chatham, Kent, the South East Counter Terrorism Unit (Sectu) said.
Ministry of Defence bomb disposal units were called, although this is routine with any suspect package.
Detective Superintendent Stan Gilmour, of Sectu, said: ''The contents of the packages are suspicious in nature and will now be sent off for forensic examination.
''Even if the contents are determined to be a viable device, they pose a very low- level threat and are unlikely to cause significant harm or damage.
''When a suspect package is reported we have a routine response which means we may need to evacuate the area if necessary until we can be sure it poses no threat to the public.
''While this can cause concern and disruption for local communities, it is a necessary precaution until we know what we are dealing with.''
Advice has been sent to the Royal Mail and to the Ministry of Defence to ensure that staff ''remain vigilant'', Sectu added.
The Queensmere shopping centre in Slough was temporarily evacuated, while cordons were placed close to all offices where packages have been found.
A Ministry of Defence spokesman said security advice has been reiterated to its personnel, while the Royal Mail said it was co-operating with the police investigation.
It is understood that a suspected package found at RAF Mildenhall in Suffolk was a false alarm and is not related to the investigation at the armed forces recruitment offices.
No details were released of attendees at the Cobra meeting in Whitehall, but it is thought likely that they included intelligence chiefs as well as Government officials and senior police officers.