The Jeju Tourism Authority confirmed on Tuesday that 38 out of the 90 Vietnamese tourists who arrived on a charter flight from the central city of Nha Trang on Nov. 14 disappeared during the final stop of their itinerary, just before their scheduled departure on Nov. 17, Korea Times reported.
The remaining members of the group have already boarded their return flight.
The tourists arrived in Jeju under a visa-free program that allows foreigners from 64 countries, including Vietnam, to stay on the island for up to 30 days without a visa, Yonhap News Agency reported.
Authorities are reviewing security camera footage to locate the missing group.
The tourists will be considered illegal migrants after Dec. 14 when their 30-day visa-free stay expires.
The travel agency that brought the Vietnamese group to Jeju failed to report the missing tourists to authorities within the required 14-day period, the Jeju Island tourism agency said.
This is not the first instance of tourists going missing on the island.
In 2022, at least 55 Thai tourists who arrived in Jeju on a package tour also disappeared during their holiday and were suspected of seeking illegal employment in various parts of South Korea.