Koh Phangan authorities called the travelers to be careful when swimming.
The warning was announced after the tragedy with the five-year-old French tourist. The boy and his family were on vacation on the Koh Phangan island. On Saturday, while swimming the boy was fatally stung by box jellyfish.
Box jellyfish is one of the most venomous creatures in the world that has ten thin tentacles up to three meters. They are terrorizing people in the Indian and Pacific Oceans.
Reference: Koh Phangan is an island in the southeastern coast of Thailand, in Northern Koh Samui.