At least 39 injured in Japan quake

An earthquake has struck in Nagano, in central Japan, injuring at least 39 people and forcing hundreds to evacuate their homes.

At least 20 people have been hurt in a 6.2-magnitude earthquake which has struck central Japan. (AAP)

At least 39 people have been injured in a magnitude 6.7 earthquake that has struck central Japan.

Television footage showed a dozen houses have collapsed in Hakuba village in the northern part of Nagano prefecture, 280km northwest of Tokyo, following the 10:08pm quake on Saturday.

Hundreds of residents were evacuated from their houses in the region as the quake caused power and water outages.

The epicentre was in northern Nagano at a depth of 10km, the Japan Meteorological Agency said.