Strong aftershock hits Tokyo area
A strong earthquake with a preliminary magnitude of 6.3 has jolted the Tokyo area.
Japan's Meteorological Agency said the quake struck at 2308 GMT on Monday. The epicentre of the quake was located just off the coast of Chiba, east of Tokyo.
There were no initial reports of injuries or damage in the prefecture. No tsunami warning was issued.
The agency said the quake was a string of strong aftershocks since the 9.0-magnitude earthquake and ensuing tsunami in northeastern Japan on March 11. The twin disasters decimated much of the region, killing up to 25,000 people and setting off radiation leaks at a coastal nuclear plant by knocking out its cooling systems.
Earlier, another strong new earthquake rattled north-east Japan - just hours after people bowed their heads and wept in ceremonies to mark a month since the tsunami.
People in a large electronics store in Sendai screamed and ran outside and mothers grabbed their children, but there were no immediate reports of more damage or injuries.
Officials said operations were not endangered at the tsunami-flooded Fukushima Dai-ichi nuclear complex, where power was cut by the aftershock but quickly restored. Japan's meteorological agency measured the aftershock at a magnitude of 7.0, but a US monitor said it was 6.6. The epicentre was just inland and about 100 miles north of Tokyo.
The Fukushima Dai-ichi plant is still leaking radiation after its cooling systems were knocked out by the tsunami, and the government has urged people in five additional communities near the plant to leave within a month, citing concerns about long-term health risks from radiation.
People who lived within a 12-mile radius around the plant have already been evacuated.