Bathers have been warned to be on the look out after potentially deadly Portuguese man-o’-war was spotted off the Islands.

One of the creatures washed up on Porthmeor beach at St Ives on Monday - and marine officers have revealed that more were seen off Scilly earlier this month.

The find at St Ives is only the sixth in British waters since 2003 and is thought to have blown onto the shore after a weekend of strong winds in the region. Experts now believe there could be manyothers in the area.

Peter Richardson of the Marine Conversation Society said: “Contact with the tentacles results in agonising stings that leave painful lesions, and a few have resulted in fatalities. Victims can suffer intense fever and anaphylactic shock.

“Children in particular are at risk. Beach users should be aware that these animals can present a serious threat.

“A conservative estimate would probably say there are something like tens on the British coast, but there could be more, we don’t know yet. They are quite rare and it’s only when you get strong south-westerly winds like over the weekend that they wash up.

“We are not expecting swarms of them to wash up and start stinging people, so there is no need to panic.”

Anyone spotting a man-o’-war is asked to call the Cornwall Wildlife Trust Marine Strandings Network hotline on 0845 201 2626.