A computer system failure caused massive delays and cancellations of flights of Jin Air Co., a budget carrier, on Friday.

The airline's passenger service system was down for 10 hours from 6:30 a.m., leaving thousands of passengers stranded at airports across the country.

"The computer system failure occurred due to a problem in the server in Germany," Jin Air said.

The system was restored at 4:40 p.m., it added.

"We apologize for causing huge inconvenience to our customers. We will examine and supplement the current systems and work procedures," the company said.

As of 4:40 p.m., 15 out of 126 Jin Air flights scheduled for the day were canceled and the rest were delayed, including 42 for more than one hour.

The system error disrupted online booking and check-in systems. The airline processed the check-in work manually during the 10 hours.

To ease disruptions, its sister company Korean Air flew 10 alternative flights for the route between Seoul and the southern island of Jeju in the afternoon. (Yonhap)