Nearly 16,000 people have used "flights to nowhere" offered by South Korean airlines since the sightseeing flights were introduced late last year, the customs office said Monday.

The Korea Customs Service (KCS) said 15,983 passengers used a total of 152 international flights designed for the purpose of the air journey, not the destination, between December 2020 and May 2021.

Passengers using the flights have bought duty-free products worth 22.8 billion won ($20 million) over the past six months, according to the customs office.

Seven airlines, including top carrier Korean Air Lines Co. and its local rival Asiana Airlines Inc., have run such flights since the government permitted the sightseeing flights to help support the pandemic--hit airline and duty--free sectors.

The program will be temporarily run until the end of this year.

Flights to nowhere start and end at the same airport and offer tax-free sales, while passengers are exempt from mandatory COVID-19 testing and the quarantine process after arrival.

Low-cost carrier Air Busan Co. has operated the largest number of such flights with 35, followed by its rival Jeju Air Co. with 34 and Jin Air with 33. (Yonhap)