A World War Two bomb containing 290lb (131kg) of “high explosives” has been found in Portsmouth harbour.
The ordnance was discovered by a dredger in the water in the early hours, the Royal Navy said.
Specialist divers at the scene said the bomb poses a “very serious threat”. It has since been towed out to sea.
All ferries were stopped and trains between Portsmouth and Southsea station and Portsmouth Harbour were suspended, but have since started running again.
There were also extensive road closures in the area, affecting access to Gunwharf Quays.
The Royal Navy said the device, believed to be a German SC250 that weighs 500lb (226kg), had been removed from the harbour.
Lt Mike St Pierre, the officer leading the bomb disposal team, had said: “My team is assessing the situation to work out how we can remove the bomb swiftly and safely with the help of the contractors, the Queen’s Harbour Master, Hampshire Constabulary and our operations centre.
“As always the Royal Navy stands ready to respond to these call-outs and keep people safe. Despite being old, these devices can pose a very serious threat.”
Hampshire Constabulary said it had “activated a pre-arranged multi-agency plan” with Ministry of Defence Police, the Royal Navy, Portsmouth City Council and other organisations.
“Our priority is to ensure public safety and minimise community disruption while the ordnance is detonated by the Royal Navy Explosive Ordnance Disposal,” the force said.
It advised residents to stay in their homes, open the windows and move away from the outer walls.
Dredging is being carried out to deepen and widen a four-mile (7km) channel to allow the the navy’s new 65,000-tonne aircraft carriers to dock.
Several devices have been found in the harbour since work started in September.
The most recent discovery was a British-made Armstrong Whitworth device found in the early hours of Friday morning, the Royal Navy has said.