The 500 pound World War Two device was picked up during dredging work.
Woman Stabbed In Portsmouth
Police have arrested two men after a woman was stabbed in the back as she walked in a busy shopping street.
The 35-year-old victim was attacked outside Barclays Bank in London Road, Portsmouth, Hampshire, at 3.20pm on Saturday.
Eyewitness Gary Hale told the Portsmouth News: "There was a woman with a knife sticking out of her back. It was awful.
"I went over straight away and another woman was screaming for an ambulance. She looked in shock so I kept talking to her to tell her that she was going to be okay but I could tell she was petrified.''
It is understood that the woman's injuries are not thought to be life-threatening.
A Hampshire Police spokesman said: "A 42-year-old man of no fixed address has been arrested on suspicion of attempted murder. He is in police custody. A 41-year-old man from Portsmouth remains in police custody. He was arrested on suspicion of conspire to murder.
Anyone with information is asked to call 101.
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.
Two Girls Indecently Assaulted Last Sunday
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