The 500 pound World War Two device was picked up during dredging work.
Security Guard Robbed Outside Tesco's
Officers are appealing for witnesses and anyone with information to come forward after a robbery of a security officer in Bournemouth.
The incident, took place at approximately 10.40am today, Tuesday 31 January 2012, outside the Tesco Express along Shillingstone Drive.
The G4S security officer had collected a quantity of cash from the shop, returned to his van to deposit it inside when he was confronted by a man who demanded money.
-The offender was dressed in black and wearing a balaclava.
A significant amount of cash, contained within different coloured plastic bags, was stolen along with a set of G4S keys.
Detective Constable Jo Shewbridge, of Bournemouth CID, said:
"I need to trace a dark green small vehicle with a hatchback similar to a small Mazda that left the scene with the offender.
"I am also keen to trace the occupant or occupants of a dark blue vehicle, seen in the area at the time, as they may have witnessed the getaway vehicle leaving the scene.
"I am appealing for witnesses, and anyone with any information about this incident, to contact police as soon as possible."
Witnesses and anyone with information should call Dorset Police in confidence on 101 quoting incident number 31:129. Alternatively, call the free and anonymous Crimestoppers line on 0800 555 111 where mobile phone tariffs may apply.
640 men were killed when the South African troop carrier was hit by a cargo ship in 1917.
The 79-year-old man suffered a serious head injury in the Cranmer Road car park in Winton.
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