An earthquake with a preliminary magnitude of 7.0 struck off northern Japan on Friday, the US Geological Survey (USGS) said.
The USGS recorded the quake at 0305 GMT.
It later put the depth of the quake at a relatively shallow 10 km (6 miles).
The epicentre of the quake was located 275 km (170 miles) northeast of Kuril'sk in the Kuril Islands, the USGS said.
There was no tsunami warning issued immediately after the quake.
The quake rocked towns in the northernmost Japanese prefecture of Hokkaido.
"We have received no reports of damage so far," a spokesman at the Hokkaido police said, adding there were no reports of injuries.