Tourists have been prohibited from entering the water along a seven-mile section of Spain’s Costa Blanca due to the presence of rare sea creatures with a potentially lethal sting.

The beaches in the municipality of Guardamar del Segura, just north of Torrevieja, have raised red flags following sightings of blue dragons, labeled as ‘the most beautiful killer in the ocean.’

Known scientifically as Glaucus atlanticus, this sea slug feeds on venomous creatures like the Portuguese man o’war, accumulating their stinging cells in large quantities.

This concentration process makes the blue dragon’s venom considerably more potent than that of the creatures it feeds on. If touched or accidentally stepped on, it can discharge these stinging cells into human skin.

Typical symptoms of the blue dragon’s sting include nausea, pain, vomiting and, in some cases, dangerous allergic reactions.

Although most stings are not life-threatening, they can be deadly for individuals with severe allergies, including children or those with cardiac or respiratory issues, as well as people stung multiple times.

Guardamar del Segura’s mayor, Jose Luis Saez, confirmed the restriction on water access yesterday, stating on his official X account that this order would remain until further notice: ‘Red flag on the beaches of Guardamar.’

‘Bathing is prohibited following the appearance on Vivers Beach of two specimens of Glaucus atlanticus, known as the Blue Dragon.’

He added: ‘We remind people that despite its bright and striking colour and it’s small 1.5 inch size, they should stay away from this animal because of its sting.

‘Guardamar del Segura Town Hall has has launched a preventive operation to detect possible specimens carried by ocean currents.

‘Town hall workers are closely following the evolution of the situation and will inform people about the different measures to be taken.

‘If you see one of these creatures don’t touch it, even with gloves on, alert lifeguards and other authorities.

‘If you get stung, wash the area affected with salt water and head to your nearest first aid point or health centre.

‘These creatures are poisonous and their stings can cause nausea, pain and vomiting.

‘For the time being and until further notice, bathing in the sea is prohibited.’

Vivers Beach, a natural stretch of coast south of the Segura River and north of La Babilonia Beach, was said to be full of people yesterday although less people than normal were in the sea defying the bathing ban order and risking heavy fines.

Lifeguards with loudhailers were expected to remind tourists and locals today about the prohibition according to local reports, although sunseekers will still be allowed to head to beaches even if they don’t take a dip in the sea.

Red flags went up at Santa Barbara beach in La Linea de la Concepcion near Gibraltar on Sunday after police received an emergency call about a blue dragon sighting and six were later found on the shoreline.

It was reopened to bathers the following day, with a yellow warning flag up instead of the red one.

Guardamar Del Segura’s mayor Jose Luis Saez announced around midday today local time beaches in the municipality had reopened but bathers were still being urged to exercise caution.

He said: ‘Yellow flags are now up on the beaches of Guardamar following the closure of the special surveillance operation due to the presence of two blue dragon specimens.

‘Municipal services, police and lifeguards remain alert to developments in the situation.’

Yellow flags mean swimming is allowed but caution is advised and it’s best to stay close to the lifeguard zone.

This is not the first time dangerous sea creatures have caused swimmers to be banned from the water in Costa Blanca.

In 2018, bathers were told to avoid the ocean after the reappearance of Portuguese Men O’War.

An 11-year-old boy was rushed to hospital after being stung by one of the jellyfish-like creatures on the few beaches that remained open on some of the most popular parts of the coastline with British holidaymakers.

The red flag was also hoisted at La Marina beach near Elche – where the youngster was hurt – after he was stung.

Lifeguards removed the animal’s tentacles from his arm but he was taken to nearby Elche Hospital after complaining of stomach and neck pain.

He was discharged a few hours later after receiving treatment.

Local reports said nearly 75 miles of Costa Blanca coastline had been declared off limits.

This is a breaking news story, more to follow.