Army bomb experts blew up the grenade

The device was found on Saturday by 16-year-old Nathan Courtney who is on holiday at a nearby caravan park.

He brought the grenade to his father, John, who placed it in a bucket of water and called the police.

"My son had just come up from off the beach and he showed me the device, I knew right away it was a hand grenade of some sort," he said.

"It was a bit corroded and I saw that there was a pin still in it."

Sergeant David Gowdy urged the public to call the police if they find suspicious objects like the grenade.

"Fortunately it is quite unusual," he said.

"But my advice would be that if they do find something suspicious on the beach to report it straight away to the police and not to handle it.

John Courtney said his son brought him the grenade

"We will assess the situation and then, if need be, call in the Army."

The area around the park on the Ballywalter Road was cleared during the operation.

It was the Belfast teenager's second brush with danger in as many weeks.