Korean Air's logo is seen in this photo taken from the company's Cabin Crew Training Center in Seoul, June 27. Reuters-Yonhap

The transport ministry said Thursday it has imposed fines on Korean Air, Delta Air Lines and Air Astana JSC for violating Korea's aviation laws during operations.

Korean Air, Korea's leading carrier, was fined 25 million won ($17,221) for keeping passengers on board for four hours and eight minutes while the aircraft was on the runway during takeoff preparations on its Incheon-Delhi flight on July 23.

By law, aircraft with passengers on board cannot remain still on the tarmac for more than three hours for domestic flights and four hours for international flights.

Delta Air Lines was fined 35 million won for keeping passengers on the runway for four hours and 58 minutes during its Incheon-Atlanta flight on Aug. 24, and also failing to report the fares for its new Incheon-Salt Lake City route to the ministry before selling tickets.

Air Astana was fined 10 million won for failing to properly report fare details for its Incheon-Astana route, according to the ministry. (Yonhap)