A powerful 7.4-magnitude earthquake struck off the northeastern coast of Japan on April 20, prompting tsunami warnings and widespread disruption to transport services, with authorities urging residents to move away from coastal areas.

The Japan Meteorological Agency said the quake occurred at a depth of 10 km in the Pacific Ocean. Tsunami waves of up to 3 metres were forecast along parts of the coast, particularly in Iwate Prefecture, Aomori Prefecture and Hokkaido.

Prime Minister Sanae Takaichi announced the formation of an emergency task force and appealed to residents in affected regions to evacuate to safer locations.

A public broadcaster aired visuals of ships leaving Hachinohe Port as a precaution, while emergency alerts urged immediate evacuation. Officials warned people to stay away from coastal zones as waves were expected to reach shore.

Bullet train services between Tokyo and Aomori were suspended following the tremor, according to Kyodo News. The quake registered an “upper 5” on Japan’s seismic intensity scale, indicating strong shaking capable of causing structural damage, including the collapse of weaker concrete walls.

Power companies, including Tokyo Electric Power Company and Tohoku Electric Power, said inspections were underway to assess any impact on infrastructure.

Although no nuclear power plants are currently operational in Hokkaido and the Tohoku region, Tohoku Electric Power said it was checking the Onagawa Nuclear Power Plant, which is shut down, for potential damage from the quake and any tsunami effects.

Japan, located along the seismically active Pacific Ring of Fire, experiences frequent earthquakes and accounts for a significant share of global tremors of magnitude 6.0 or higher.

Authorities said monitoring was ongoing, with further updates expected as assessments of damage and tsunami impact continue.