Vehicles are stuck in traffic due to unseasonal heavy snowstorm in Gwangju, South Jeolla Province, March 18. Newsis

Unseasonal heavy snow pounded Seoul and the central regions beginning early Tuesday morning, disrupting rush-hour traffic across the capital areas.

Amid an unexpected heavy snow advisory issued the previous day, Seoul had received 11.9 centimeters of snow as of 8:20 a.m., compared with 13.8 cm in Uijeongbu of Gyeonggi Province and 19.9 cm in Goseong of Gangwon Province, the Korea Meteorological Administration (KMA) said.

It is known to be the latest heavy snow advisory issued in Seoul.

Traffic congestion occurred in various parts of Seoul as cars slowed down on slippery roads.

The average traffic speed in central Seoul fell to 17.9 kilometers per hour as of 7 a.m., according to the Seoul city government.

The snowfall also caused numerous accidents and vehicle-to-vehicle collisions throughout the capital, as cars skidded on the snowy roads.

In Ansan, south of Seoul, an Uzbek man in his 20s died in a single-car accident early Tuesday morning, in which his car crashed into a median barrier on an apparently slippery road.

Flights were also disrupted, with four flights scheduled to depart from Gimpo, Jeju island, Yeosu and Wonju canceled due to strong gales and aircraft de-icing, according to Korea Airports Corp. Five other flights were delayed as of 8 a.m.

At Incheon International Airport, Korea's main gateway, five flights were delayed, but none were canceled as of 8 a.m., according to its operator.

To ease the morning rush hour, Korea Railroad Corp. said it added 14 train services to subway lines in the capital area.

A company employee, surnamed Lee, 28, who commutes from Seongnam, Gyeonggi Province, to Yeouido in western Seoul, said he is already tired in the morning because there are so many people using the subway.

The KMA said the snow is expected to stop falling nationwide during Tuesday. (Yonhap)