South Korea is preparing to evacuate tens of thousands of scouts – including more than 4,000 from the UK – from a coastal jamboree site as Tropical Storm Khanun looms, officials said.

The World Organisation of the Scout Movement said it received confirmation from South Korea’s government of the early departure for all participants in the south-western county of Buan.

That means quickly moving tens of thousands of scouts – mostly teenagers – from 158 countries out of the storm’s path.

South Korea’s weather agency reported that Khanun was about 205 miles north-east of the Japanese island of Okinawa as of 9am local time on Monday. It was expected to make landfall in South Korea on Thursday morning, packing high winds.

Large swathes of the country’s south, including Buan, could be affected by the storm as early as Wednesday, the agency said.

President Yoon Suk Yeol’s office said he called for “contingency” plans, which could include relocating the scouts to hotels and other facilities in the country’s capital, Seoul, and nearby metropolitan areas.

Kim Hyun-sook, South Korea’s minister of gender equality and family, said officials are trying to arrange new cultural events and activities for the scouts before they leave, including a possible K-pop concert at a Seoul soccer stadium on Friday to go with the closing ceremony.

When asked whether the scouts’ departure from Buan should be seen as an early end for the jamboree, Ms Kim said: “We don’t see it that way.

“We are creating new programmes with regional governments away from the campsite, so it could be said the jamboree is widening.”

Hot temperatures have already forced thousands of British and American scouts to leave the site, which is made on land reclaimed from sea. Hundreds of participants had been treated for heat-related ailments since the jamboree started on Wednesday.

Long before the event’s start, critics raised concerns about bringing such large numbers of young people to a vast, treeless area lacking protection from the summer heat.

Organisers are scurrying to come up with plans to evacuate the scouts ahead of the storm’s arrival.

Choi Chang-haeng, secretary-general of the jamboree’s organizing committee, said officials have secured more than 340 evacuation venues, including community centres and gyms, in regions near Buan.

About 40,000 scouts – mostly teenagers – from 158 countries came to the jamboree, built on land reclaimed from the sea.

About 4,500 were from the UK, representing the largest national contingent, while about 1,000 were from the United States.