A 5.9 magnitude earthquake struck eastern Japan on Wednesday, according to the US Geological Survey (USGS). Japan's public broadcaster NHK said that no tsunami warning was issued.
The epicentre of the quake was located 18 kilometres northeast of Daigo, a town in the northern Kanto region, at a depth of 10 kilometres, according to the USGS. There were no immediate reports of damages or injuries.
Japan's meteorological agency put the magnitude at 6.3, while the USGS measured it at 5.9.
Meanwhile, Japan's nuclear regulator said there were no irregularities at the Fukushima Daiichi nuclear plant where one of the world's worst nuclear accidents unfolded after a March 2011 earthquake and ensuing tsunami.
NHK said the operator of Tokyo Electric Power Co was checking for any impact of the quake on the plant but the nuclear regulator reported no irregularities.
Japan sits at the junction of four tectonic plates and experiences a number of relatively violent quakes every year. But rigid building codes and strict enforcement mean even strong tremors often do little damage.
The 2011 magnitude 9 quake was the strongest ever recorded in Japan, and it generated a tsunami that knocked out the Fukushima plant, causing the worst nuclear crisis since the Chernobyl atomic reactor disaster in Russia a quarter of a century earlier.
About 25,000 people were affected by the tsunami along Japan's northeast coast.
In April, two strong earthquakes hit southern Japan's Kumamoto prefecture followed by more than 1,700 aftershocks, leaving at least 50 dead and causing widespread damage.