
Tokyo: A major earthquake struck northern Japan on Monday, prompting an official tsunami warning and evacuation order. Tidal waves of up to three metres (10 feet) could hit the country's northern coasts almost immediately, Japan's Meteorological Agency (JMA) said.
"Evacuate immediately from coastal regions and riverside areas to a safer place such as high ground or an evacuation building," the agency said, adding that property damage was expected.
"Do not leave safe ground until the warning is lifted," the JMA said. The area covered by the order extended as far north as Hokkaido, they said.
The agency recorded an 80-centimetre (32-inch) tsunami near Kuji port in Iwate prefecture following the 7.4-magnitude earthquake.
"For those of you who live in areas for which the warnings have been issued, please evacuate to higher, safer places such as higher ground," Prime Minister Sanae Takaichi told reporters, adding that the government was trying to confirm whether there were any casualties or property damage.
Shinkansen bullet train services between Tokyo and Aomori, the northernmost city on Japan's largest island of Honshu, have been suspended for the time being.
The shadow of Fukushima
It has been fifteen years since the most powerful earthquake ever recorded in Japan struck the Tohoku region, killing some 20,000 people and prompting a nuclear disaster at the Fukushima Daichii power plant.
Located on the Pacific "Ring of Fire" known for its volanic and tectonic activity, Japan has been a hotspot for earthquakes and tidal waves throughout its history.
Most recently, dozens of people were injured in a December quake of the coast of Aomori prefecture. The JMA has twice issued warnings about possible "megaquakes" it believes could one day occur along the Nakai ocean trough.
The 800-kilometre (500-mile) trench is where the Philippine Sea tectonic plate is slowly slipping undernearth the continental plate that includes Japan. Officials estimate such a megaquake could kill hundreds of thousands of people and cause trillions of dollars in damage.