Beachgoers have been warned after dozens of Portuguese men o’ war washed ashore on South Shore beaches.

The ‘jellyfish’ can inflict a painful sting to those who come into contact with their tentacles.

The Ministry of the Environment said several men o’ war have been seen on Horseshoe Bay and Elbow Beach.

The ministry said in a press release: “The Portuguese man o’ war can be identified by a bluish, gas-filled float on top of the water. Its long tentacles drift below the surface of the water and often they are difficult to see. These tentacles cause very painful stings.

“Stay away and do not touch them, even if they are on shore as the tentacles can still be very venomous.”

Those who do suffer stings are advised to carefully remove tentacles without using bare hands to prevent further stings. The affected area should then be treated with seawater to flush away any remaining tentacles.

To treat the pain, hotpacks or hot water should be used for up to 30 minutes, followed by burn ointment and a light dressing. Pain relief medication can also be used.

March to June are considered the peak month for Portuguese man o’ war stings on the island, with them often being washed ashore after a storm or period of strong winds.

While often referred to as jellyfish, man o’ war are actually siphonophore — a floating colony of specialised individual animals called zooids or polyps. Each of these organisms are bound together so they require each other for survival.

The organisms usually float on the open ocean using the venom in their dangling tentacles to paralyse their prey.

While individual stings can result in red welts on the skin that linger for up to three days, larger numbers of stings can result in more serious issues.