The prime minister’s office said it had set up a crisis management team.
Japan is one of the world’s most seismically active countries, sitting on top of four major tectonic plates along the western edge of the Pacific “Ring of Fire”.
The archipelago, home to around 125 million people, typically experiences around 1500 jolts every year and accounts for about 18 percent of the world’s earthquakes.
The vast majority are mild, although the damage they cause varies according to their location and the depth below the Earth’s surface at which they strike.
In 2011, a magnitude-9.0 quake triggered a tsunami that left 18,500 people dead or missing and caused a devastating meltdown at the Fukushima nuclear plant.
– Agence France-Presse