MOSCOW — A major earthquake hit a distant, sparsely populated region of Russia's Far East early Friday, causing unknown damage and possible casualties, an emergency official said.

The U.S. Geological Survey and Japan's Meteorological Agency estimated the quake's magnitude at 7.7.

The quake hit around 12:45 p.m. local time in Koryak region, nearly 7,000 kilometres east of Moscow and some 1,000 kilometres north of the largest city in the area, Petropavlovsk-Kamchatsky, said Oleg Kotosanov, a duty officer with the regional emergency situations ministry.

Kotosanov said by telephone there were reports of damage in some villages of the Pacific region and emergency officials were flying by helicopter to several locations. Federal emergency officials in Moscow said they had no information about the quake.

Russian news agencies said in the coastal village Tilichiki structures and buildings, including a school, a hospital and a local airport, had been partially or wholly destroyed, along with municipal electric and heating systems. The agencies said some injuries had been reported.

"It's the largest event in this area since 1900," said A.B. Wade, a spokeswoman for the USGS.

"It's a sparsely populated area; up to 2,000 people were exposed to intensive shaking."

The Russian quake posed no tsunami risk to the western United States and Canada, the West Coast and Alaska Tsunami Warning Center said.

Russia's northern Pacific coast sits along a major tectonic plate and is frequently hit by earthquakes and volanic eruptions.

By comparision, the great San Francisco earthquake of 1906, which destroyed more than one-half of the city's buildings and left between 3,000 and 6,000 people dead 100 years ago this week, was estimated at a magnitude of between 7.7 and 7.9.

The USGS said the quake occured about 50 kilometres below the Earth's surface.