Singapore Airlines changed the route of its Seoul-Los Angeles flights in July due to concerns over North Korean missiles, Singapore's Channel NewsAsia reported Tuesday.
An official at the Ministry of Land, Infrastructure and Transport said, "It appears that Singapore Airlines is flying over Busan and the east coast of Japan rather than flying through Gangwon Province and the East Sea."
North Korea often lobs its missiles into the East Sea.
When the North launched an intercontinental ballistic missile late last month, pilots from two Korean Air passenger planes said they spotted the engine blasts and reported the sighting to the Japanese aviation authorities.
Any missile launches must be reported to the International Civil Aviation Organization to assure the safety of civilian aircraft. North Korea joined the ICAO in 1977, but the last time it warned the organization of an impending missile launch was in February 2016.