A 6.9-magnitude earthquake struck Thursday off the coast of far eastern Russia, the US Geological Survey said, with Russian officials saying the tremor caused no damage or casualties.

The USGS said the quake hit off the Kuril islands in the Pacific at 1405 GMT at a depth of 53 kilometres (33 miles).

Russia's emergency ministry said the quake's magnitude was 6.3, with the Kamchatka Peninsula's main city Petropavlovsk-Kamchatsky recording a magnitude of up to 4.

"There is no threat of tsunami, no casualties or damage," the ministry said in a statement.

The islands, some of which are claimed by Japan in a dispute going back to World War II, are south of the Kamchatka peninsula.

The USGS said an underground formation called the Kuril-Kamchatka arc is considered one of the most seismically active regions in the world.

Since 1900, seven powerful earthquakes of magnitude 8.3 or greater have occurred along the arc, the USGS said.