"A magnitude 5.9 earthquake was registered at 14:22 Saturday [03:22 GMT] near the Kuril Islands", head of the Yuzhno-Sakhalinsk seismic station Elena Semenova said.
The epicentre of the aftershocks was located at 41.9 degrees north latitude and 147.0 degrees east longitude, some 160 miles southeast of Yuzhno-Kurilsk, a regional centre on Kunashir Island, at a depth of 23 miles, she added.
According to Sakhalin Region's emergency services, there were no casualties, injuries, or damage caused by the earthquake. No tsunami alert was made.
The Kuril Islands are located in a seismically active region known as the Ring of Fire, which is constantly affected by powerful earthquakes.