A 5.2-magnitude earthquake hit central Japan on Sunday morning, Japanese and US authorities said. However, the Japan Meteorological Agency did not issue a tsunami warning.
The US Geological Survey said that the quake struck at a depth of 10 kilometres, about 30 kilometres west of Ina in Nagano prefecture at 7.02 am (6.02 am Singapore time). According to public broadcaster NHK, there were no immediate reports of injuries or damage.
NHK reported that Shinkansen bullet train services were temporarily suspended due to the jolt in central Japan. But, there was no abnormality at nuclear power plants in the region.
Japan is located at the junction of four tectonic plates and earthquakes are quite common in the country. The country sits on one of the world's most seismically active zones. But rigid building codes and strict enforcement mean even strong tremors often do little damage.
Reports say Japan accounts for about 20 percent of the world's earthquakes of magnitude-6 or greater.
A massive undersea quake that hit in March 2011 sent a tsunami barrelling into Japan's northeast coast, leaving more than 18,000 people dead or missing, and sending three reactors into meltdown at the Fukushima nuclear plant.