A 7.0-magnitude earthquake hit north-eastern Japan, affecting the islands of Hokkaido and the northern part of the Honshu island, the country's meteorological agency said.
It added that the epicentre of the quake was located at a depth of 160 kilometres. No tsunami alert has been issued.
No damage has so far been reported.
The quake was felt even in Tokyo. According to Japan's seven-grade scale of earthquake intensity, the Hokkaido island was hit by a 4-magnitude quake, while on Tokyo it was measured only at one.