A strong 6.1-magnitude earthquake struck off Hokkaido early Tuesday, the U.S. Geological Survey said.
The quake hit off the west coast of the island, about 170 km (106 miles) north of Sapporo, at a relatively deep 236 km.
The Meteorological Agency recorded it as a weaker 6.0 quake.
Japan sits at the meeting place of four tectonic plates and experiences around 20 percent of the world’s most powerful earthquakes every year.
But rigid building codes and strict enforcement mean even powerful tremors frequently do little damage.
A 7.8-magnitude quake that struck off the coast in May last year injured a dozen people.
A massive undersea quake that hit in March 2011 sent tsunami barreling into Japan’s northeast coast, killing more than 15,000 people and sending three reactors into meltdown at the Fukushima nuclear plant.
Tuesday’s temblor struck 75 km (47 miles) south of the town of Rishiri, the U.S. Geological Survey said.
It put the depth of the quake at 236 km, and originally reported the magnitude at 6.3.
The Meteorological Agency said the earthquake had only achieved a maximum seismic intensity of 3 at the surface on land, on a scale of 0-7, and posed no tsunami risk.