There was no risk that the quake had triggered a tsunami, according to the Pacific Tsunami Warning Centre (PTWC).

The USGS said the quake hit 111 kilometres (69 miles) east of the Russian city of Petropavlovsk-Kamchatsky, the administrative centre of the Kamchatka region, at a depth of 39.5 kilometres.

The survey earlier gave a magnitude of 7.5 before downgrading it.

The PTWC initially warned that "hazardous" waves of up to one metre (3.3 feet) were possible along some nearby Russian coasts.

The centre later said "the tsunami threat... has now passed".

In July, one of the strongest earthquakes ever recorded struck off the Kamchatka peninsula, triggering tsunamis up to four metres high across the Pacific and sparking evacuations from Hawaii to Japan.

The magnitude 8.8 quake was the largest since 2011, when a magnitude 9.1 tremor off Japan caused a tsunami that killed more than 15,000 people.

July's quake prompted authorities in Japan to order almost two million people to head to higher ground.

Tsunami warnings were also issued across the region, before being rescinded or downgraded.