Seismologists said the quake happened at 2:40 a.m. local time (3.40 p.m. GMT Thursday) at a depth of five kilometers to the south of Yuzhno-Sakhalinsk, the island's administrative center, which is 6,500 miles east of Moscow.
"According to the head of Emergency Situation Ministry's Nevelsk district department, windows were shattered in some buildings" the spokesman said. "No injuries or [serious] damage have been reported so far."
Powerful quakes have hit Russia's Pacific for years. A devastating earthquake destroyed the Sakhalin town of Neftegorsk of May 28, 1995 and claimed over 2,000 lives.
Over 1,200 people, including 542 children, were evacuated from the emergency zone after
a series of major earthquakes rocked the north of the Kamchatka peninsula this year. The first 7.8-magnitude quake on April 21 had an epicenter about 30 kilometers (18 miles) from the town of Khailino, the strongest in the Koryak Autonomous since 1900 Area, and injured 31 people. It also damaged about 380 houses and 25 administrative facilities in four other towns.
According to research conducted by the International Institute of Earthquake Prediction Theory and Mathematical Geophysics, there is at least a 30% probability of an earthquake with a 7.2-magnitude or higher in the area of Kamchatka and the Kuril Islands before mid-December.