Army teams from the Explosive Ordnance Disposal unit in Wiltshire were called to investigate an unexploded bomb found on Sand Bay yesterday (Thursday).
A dog walker discovered the munition and called the police, who then alerted bomb disposal teams.
Emergency services set-up a cordon and the coastguard at Weston and Clevedon was sent to establish a safe perimeter at sea.
Weston Coastguard said the ordnance was a naval shell used on warships but 'years of erosion' had made it impossible to tell if it was live or a test unit.
At around 4pm, the teams detonated the shell in a controlled explosion to minimise the risk to the public.
A spokesperson for the coastguard said: "The suspicious object was no doubt uncovered by the recent storms.
"Upon arrival of the scene, bomb disposal experts worked out it was a five pound naval shell.
"With the object safely out of harms way and a cordon in place, the army detonated their charges causing a rather loud bang.
"We would like to thank the public for their cooperation and patience and remind them to stay safe on the coast."
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