The first tsunami reached South Korea’s east coast at 0921 GMT at a height of 45 cm (1.5 ft) in the wake of a massive earthquake that hit Japan on Monday, South Korea’s meteorological agency said.
The tsunami can grow after the initial waves and may continue for more than 24 hours, the agency said in an advisory.
South Korea’s Gangwon province warned residents to take precautions and evacuate to higher ground, according to the Ministry of Interior and Safety.
South Korea’s meteorological agency earlier said sea levels in some parts of the Gangwon province on the east coast may rise after an earthquake with a preliminary magnitude of 7.6 hit north central Japan and it issued an advisory for caution.
It said tsunami waves of up to 0.3 metres could reach South Korea’s eastern shore between 0929 GMT and 1017 GMT.
Gangwon province told residents in emergency text messages to stay away from the coast and evacuate to higher ground. The city of Samcheok advised residents to move to areas higher than a three-storey building, the Ministry of Interior and Safety said.