A high magnitude earthquake measuring 8.5 on the Richter scale struck Japan's east coast today, although no damage has been reported. There was also no danger of tsunami from the quake that struck at an extremely deep area, geologists said.
The quake shook buildings in Tokyo and set off car alarms. Residential buildings swayed for nearly a minute as the quake rose in intensity at around 8.30pm, reports said.
The quake, centered off the Ogasawara islands south of Tokyo, was felt throughout much of Japan.
The US Geological Survey said the epicentre was 676 kilometres below the Earth's surface and was centered on a remote spot in the Pacific Ocean around 870 kilometres south of Tokyo.
The Pacific Tsunami Warning Centre, however, said the huge power of the quake is unlikely to trigger tsunami as it occurred deep under the ocean floor.
The quake also did no further harm to the already crippled Fukushima Dai-ichi nuclear plant, damaged four years ago in a massive 9.0 magnitude quake, or any other nuclear facilities.
The Shinkansen high speed train line had briefly stopped between Tokyo and Osaka due a power outage and some trains in Tokyo stopped for safety checks, causing some panic among commuters.
Runways at Narita Airport, the main international gateway to Tokyo, were also temporarily closed while inspections were carried out.
A football match in the city was also briefly suspended.