The number of passengers flying with Korean Air Lines Co., the country's top air carrier, dropped from a year earlier in 2013 partly due to a fall in international passengers, related data showed Sunday.

The total number of passengers on Korean Air flights came to about 23.6 million last year, down 3.9 percent from the previous year, according to the data from the Ministry of Land, Infrastructure and Transport.

Korean Air is the only airline among the country's seven flag carriers, including five low-cost carriers, whose passenger traffic shrank from a year earlier in 2013.

Korean Air attributed the drop to a large fall in the number of passengers to and from Japan, along with growing competition from budget carriers.

"Reasons for the drop in the number of passengers can be found in the weakening value of the Japanese yen and growing competition from low-cost carriers," a company official said, asking not to be identified.

The weaker yen has made prices here go up for the Japanese and cause a significant drop in the number of Japanese tourists to South Korea.

In 2013, the number of passengers to and from Japan on Korean Air flights plunged 15.4 percent on-year to some 3.91 million while Korean Air's overall international passengers dropped 2 percent to about 16.64 million.

Passengers to and from China, on the other hand, grew 7 percent on-year to 3.12 million.

The ministry earlier said the number of international and domestic passengers on flights by the country's five low-cost carriers spiked 20 percent on-year to over 15.69 million last year. (Yonhap News)