Gunwharf Quays has been evacuated this morning following the discovery of a WWII German bomb.
A spokesperson for the shopping centre has confirmed that the area has been cleared temporarily.
Police are warning members of the public to avoid the area.
Those evacuated from the area will be directed to the John Pound Centre, in Queen Street, one of two rest centres set up. The other is at Portsmouth Cathedral.
The 300m cordon will also require other areas to be evacuated, including the Wight Link terminal, Old Portsmouth, Portsmouth Harbour station, Gosport ferry station and the Hot Walls areas.