A 7.0-magnitude earthquake has struck in seas off far northern Japan and far eastern Russiabut but no damage was expected.

The Japan Meteorological Agency said sea changes were possible. No tsunami warnings have been issued.

The tremor struck around midday in the Pacific Ocean at a relatively shallow depth of 10 kilometres. The US Geological Survey measured a stronger 7.2 magnitude.

Japan and Russia both claim some of the sparsely populated islands in the remote region.

The epicentre was 58 kilometres east-northeast of Kuril'sk, Russia, and 528 kilometres northeast of Nemuro, Japan.

The nearest land is the volcanic islands of Urup, Iturup and Sumushir. Hokkaido officials said the islands were not under Japanese control.

The area is about 1,500 kilometres northeast of Tokyo.

The quake was felt in Hokkaido and much of the northern island of Japan. It was also reportedly felt in Tokyo.

"We have received no reports of damage so far," a spokesman at the Hokkaido police said, adding there were no reports of injuries.

Originally published as Magnitude 7.0 quake off Japan