UPDATE 9.33pm (AEST): A THIRD large earthquake has struck off the coast of Japan tonight.
A SERIES of strong earthquakes rattled northeast Japan today, keeping residents on edge more than a week after a devastating tremor and tsunami battered the region.
The 6.6-magnitude earthquake struck at a depth of 15km, about 568km northeast of Tokyo, at 6.44pm (8.44pm (AEDT), according to the US Geological Survey.
The tremor followed a 6.4-magnitude earthquake at 6.19pm (8.19pm AEDT). That quake struck at a depth of 27km 131km from the city of Fukushima in northeastern Japan.
Earlier, a 6.6-magnitude earthquake struck at a depth of 26km, some 312km from Fukushima, where workers continue to battle to contain radiation leaks from a stricken nuclear reactor.
No tsunami warnings or damage from the quakes have been reported.
Earlier today, radiation levels 1600 times higher than normal were recorded as far as 20km away from the Fukushima nuclear plant, according to International Atomic Energy Agency figures cited by the Kyodo News agency.[heraldsun.com.au]