A high-speed train on its way from Seoul to Busan broke down for 68 minutes in a tunnel on Friday, news reports said.

The KTX train stopped running suddenly near Busan between 3:42 p.m. and 4:50 p.m. while passing through Geumjeong Tunnel, the country’s longest, just 5 minutes from Busan station.

A mechanical malfunction is believed to have been the cause but further inspection is necessary, a spokesman of Korea Railroad Corp. said.

All the electric devices including air conditioning system stopped as well, with the only exception being the emergency lights, according to sources.

Shortly after the train arrived in Busan Station, KORAIL announced a 25 percent discount coupon as compensation for all passengers on the train.

The railroad company said that it would take all measures to prevent another such occurrence.

By Chung Joo-won (joowonc@heraldcorp.com)