Two quakes measuring 4.7 and 4.8 on the Richter scale were registered at 6:54 p.m. local time Tuesday (5:35 a.m. GMT) and 11:59 p.m. (10:59 GMT), respectively, 220 kilometers (140 miles) to the east of the Kamchatka Peninsula at a depth of 33km (21 miles), seismologists said.
Another quake, with a magnitude of 4.6 was registered at 1:39 p.m. local time (2:39 a.m. GMT) in the Sea of Japan 125km (78 miles) to the northeast of the city of Nakhodka in the Primorye Territory, a spokesman for local emergency services said.
"A 4.6-magnitude earthquake occurred at a depth of the 450km (280 miles)," he said. "No tremors were felt in the territory's coastal regions. No casualties, destruction or threat of tsunamis have been reported."
Powerful quakes have hit Russia's Pacific for years. Over 2,000 people were killed when a devastating earthquake destroyed the town of Neftegorsk on the island of Sakhalin on May 28, 1995.
This year more than 1,200 people, including 542 children, were evacuated from the north of the Kamchatka peninsula after a series of major earthquakes. The first 7.8-magnitude quake, the strongest in the Koryak Autonomous Area since 1900, injured 31 people on April 21 and had an epicenter about 30 kilometers (18 miles) from the town of Khailino. It also damaged about 380 houses and 25 administrative facilities in four other towns.