Korean air carriers are launching flights to small cities in Japan as they seek to find new growth engines amid fierce competition on major Korea-Japan routes.

Korean Air Lines Co. announced Monday that it has resumed operations on its Incheon-Kumamoto route after a 27-year hiatus.

Initially launched in April 1991, the route had been suspended since 1997.

Kumamoto, located in central Kyushu, is renowned for its natural attractions such as Mount Aso, the world’s largest caldera volcano, and the historic Kurokawa hot spring village.

Asiana Airlines Inc. restarted its Incheon-Kumamoto route in October, resuming services after nearly 9 years of suspension.

The airline is also set to launch a new route to Asahikawa, a popular winter destination in northern Hokkaido, in mid-December.

Low-cost carriers (LCCs) are also expanding their presence by flying to new destinations.

Jeju Air Co., for example, operates routes from Incheon to Matsuyama, Shizuoka, Hiroshima, Oita, and Kagoshima.

Matsuyama, known for its historic Dogo Onsen hot spring, offers convenient transportation and high revisit rates. In December, Jeju Air will introduce a Muan-Nagasaki route to cater to regional airport travelers.

Air Seoul launched its first international route, Incheon-Takamatsu, in 2016 and has carried 250,000 passengers over the past two years, achieving an average load factor of 86 percent. Eastar Jet Co. plans to begin operations on its Incheon-Tokushima route in late December, offering promotional fares starting at 49,900 won ($35.63) one way.

The focus on smaller cities comes as airlines face declining margins on oversaturated routes to major hubs like Tokyo, Osaka, and Fukuoka, where intense competition has driven aggressive fare discounts.

Prolonged yen depreciation and the development of new routes have fueled a surge in travel demand to Japan.

According to the Ministry of Land, Infrastructure, and Transport, passenger traffic on Korea-Japan routes reached 20.57 million from January to October, nearing the 2018 record of 21.35 million.

Jeju Air leads the market among domestic carriers, with a 15.3 percent share and 3.15 million passengers.

“The combination of frequent short-trip trends and the weak yen has sustained rising demand for travel to Japan,” said a Jeju Air official.