Tsunami alert after powerful quakes strike off coast of Russia

Three powerful earthquakes struck off the coast of Russia's far east on Sunday, triggering a tsunami alert, the US Geological Survey said.

Earlier 5.0-magnitude and 6.7-magnitude earthquakes did not initially trigger a tsunami alert, but were followed by a 7.4-magnitude quake at 0849 GMT, prompting the USGS to warn that "hazardous tsunami waves are possible" within 300 kilometres (186 miles) of the epicentre in the Pacific, off the city of Petropavlovsk-Kamchatsky.

The Kamchatka Peninsula is a convergence point for the Pacific and North American tectonic plates, making it one of the world's most seismically active regions.

According to the US National Geophysical Data Center, the Russian peninsula, which separates the Sea of Okhotsk from the Pacific Ocean, is considered "one of the most earthquake-prone regions in the world."

Since 1900, seven major earthquakes measuring 8.3 magnitude or higher on the Richter scale have occurred along the peninsula.