Playing catch with the dogs will never be the same for one man in the UK.

Part of an Essex beach was sealed off when a walker picked up the barnacle-encrusted 'stone' for his pet to chase along Harwich beach.

In a brilliant stroke of fortune a passing off-duty military explosives expert saw the grenade being thrown and realised what it was and it's potential danger.

He alerted the police and coastguard, who set up a 30-yard cordon around the grenade. It was later taken away by explosive ordnance disposal (EOD) officers.

This is not the first time an incident like this has happened on the Harwich beach in Essex. Five have been found in the past couple of months.

Inspector Paul Butcher from Essex Police said: ''It would appear that the grenades might have been in a crate that ended up in the sea during the Second World War.

''That crate might be breaking up or has been disturbed by dredging in the port and has resulted in these five devices being washed ashore along the same stretch of beach.

''We are asking people to be vigilant if visiting this beach and to dial 999 if they find any of these devices."