Visitors at Sentosa's Siloso Beach will not be allowed to enter the water, following sightings of box jellyfish. In a Facebook post at around 10pm last Friday, Sentosa said no one will be allowed to swim "until further notice".
A box jellyfish was sighted in the waters of Siloso Beach last Friday, according to the post. "The safety and well-being of everyone on Sentosa are of utmost importance to us," it said. Beach and water surveillance has been stepped up.
Some species of box jellyfish have highly venomous stings that could be fatal. Victims could also drown as a result of pain or paralysis from being stung.
At least two people have reportedly been hurt by box jellyfish in Singapore waters this year.
In March, the creature was spotted at East Coast Park, where Australian Jade Dyson, 28, was stung while swimming. She told The New Paper that she "could barely walk and the left side of her body was convulsing and shaking".
Three confirmed sightings followed in July in Sentosa Cove, Tuas and on Lazarus Island, conservation group Marine Stewards noted in a Facebook post on July 18.
The creatures are usually found in tropical regions off the coasts of Malaysia, the Philippines and Australia.
Victims stung by the jellyfish are advised to get to the shore immediately and seek medical attention. They should avoid rubbing the wound to prevent the release of more venom. First aid can be performed by flooding the injured area with seawater for at least 30 seconds and then removing the tentacles using a towel or tweezers.
Individuals should refrain from urinating or pouring freshwater on the wound.
Anyone who spots a box jellyfish should contact beach patrol officers or Sentosa Rangers on 1800-726-4377.