By Soo-hyang Choi

SEOUL South Korea's interior minister urged on Thursday organisers of a global scout jamboree to take "all available measures" to ensure the safety of the event after more than 400 participants suffered heat-exhaustion amid scorching temperatures.

The 25th World Scout Jamboree kicked off on Tuesday as authorities issued the highest-level warning for extreme temperatures for the first time in four years.

"Most of them were experiencing mild symptoms, such as headache, dizziness and nausea and all returned to their camp sites," a Jeonbuk Fire Service official said, referring to the scouts.

Parts of South Korea have been roasting in temperatures over 38 degrees Celsius (100.4 Fahrenheit) this week, and the heat has killed at least 16 people, according to official data.

Interior and Safety Minister Lee Sang-min has ordered more ambulances, shuttle buses and air conditioners to remain on standby to ensure the safety of the scouts, his office said.

About 43,000 scouts from around the world are expected to take part in the jamboree, scheduled to run to Aug. 12. The event is being held in a massive sea reclamation project in the western county of Buan, and the opening ceremony was attended by President Yoon Suk Yeol and British TV adventurer Bear Grylls.

The organising committee for the global scout jamboree was not immediately available for comment.

(Reporting by Soo-hyang Choi; editing by Miral Fahmy)