WASHINGTON - A POWERFUL 7.3 magnitude earthquake struck early on Monday an area in the Sea of Okhotsk in Russia's Far East, the US government reported, revising a previous figure of 7.0.

The epicentre of the earthquake, which occurred at 8.02pm (5.02pm Singapore time), was located 315 kilometres west-northwest of the city of Petropavlovsk-Kamchatskiy, Russia, according to the US Geological Survey.

The reading was based on the open-ended Moment Magnitude scale, now used by US seismologists, which measures the area of the fault that ruptured and the total energy released.