Young people are being warned about the potentially tragic consequences of ’tombstoning’ off the Cornish coast.

Cornwall Council has issued new danger signs to look out for, including submerged objects that can cause serious injury.

Since 2004 there have been 142 tombstoning incidents requiring an emergency response and 12 people have died as a result of the activity. Spinal and limb injuries are amongst the most common, and these can be life-changing, says the local authority.

Councillor Rob Nolan, cabinet member for the Environment and Public Protection, said: ’Tombstoning is a popular activity but it can have severe and life-threatening consequences. Unfortunately over recent years it has gained attention for the wrong reasons, with a number of people killed or seriously injured.

’We’re urging everyone to consider the risks to yourself and others and consider the dangers. Look out for warning signs and don’t jump into the unknown.’