Britain's main Royal Navy base has been partially evacuated over a suspicious package believed to have been posted from Northern Ireland.
Bomb disposal experts have been called to HMNB Devonport in Plymouth, Devon, and a large area has been cordoned off in the security alert.
The road has been sealed off in the Granby Gate area after police and Royal Navy teams received a phone call at around 11am.
The incident has happened near the HMS Vivid site, the Royal Naval Reserve unit which has been evacuated.
Devonport is the largest naval base in Western Europe and is the sole nuclear repair and refuelling facility for the Royal Navy.
It is one of three operating bases in the United Kingdom for the Royal Navy.
One witness said they believe a package sent from Northern Ireland may have sparked the alert.
The Royal Navy confirmed that a suspicious package was reported at HMS Vivid.
One local witness said: "We've been told to stay in work because a suspect package was found.
"The police are at the top of the hill about 100 metres away."
Mark Hart, who works at the nearby Lugger pub, said: "I had just arrived when the workmen told me about what was going on.
"There were about 22 of them out on the road and they had been evacuated. They were packing up and had been told to go home.
"Apparently a suspicious packet had been sent to HMS Vivid and it was from Northern Ireland.
"The area behind the pub has been cordoned off."
Police said they were called by Royal Navy Explosive Ordnance Disposal shortly before 11am regarding a suspect package.
Bomb disposal experts have attended the scene at the Devonport base and confirmed the suspicious package was "benign".
A Royal Navy spokesman said the package did not pose a threat to anybody.