The device was discovered by the Army's 33 Engineer Regiment's Ordnance Disposal team on Monday, during a three-week survey of Studland Beach.

The beach was cordoned off on Tuesday so the bomb could be destroyed in a controlled explosion.

A spokesman for The National Trust, which owns the beach, said it is thought to be larger than a 100lb (45kg) explosive found there last year.

Munitions increase

Studland Beach was the site of live rehearsals for the D-Day landings during World War II, and munitions from the era still surface.

A spokesman for The National Trust, said: "Recent coastal erosion and the drying out of the wetland areas at Little Sea have seen an increase in the number of munitions found by the public."

In October, last year, a survey by the Ordnance Disposal team found a bomb on Knoll Beach.