TOKYO (REUTERS, AFP) - A strong and shallow earthquake struck Japan's north-west coast around Niigata prefecture on Tuesday night (June 18), triggering a small tsunami, shaking buildings and cutting power to around 9,000 buildings.
The magnitude 6.4 quake, according to the US Geological Survey (USGS), lasted for as long as 20 seconds and damage included a landslide that struck a road, according to public broadcaster NHK. There were no initial reports of fatalities or fires.
NHK said tsunamis of several centimetres struck parts of the Niigata coast. Authorities issued a 0.2-1.0 metre tsunami warning for the region. The warning was lifted after 1am local time (midnight Singapore time).
A tsunami of up to one metre could cause some flooding and damage in low-lying coastal areas and river banks, though much of Japan's coastline is guarded by sea walls.
"We will work closely with local authorities to provide any disaster measures including lifesaving and rescue operations and have instructed officials to provide information in a timely and accurate manner," Chief Cabinet Secretary Yoshihide Suga - the top government spokesman - told a media briefing.
The quake struck at 10.22pm local time at a depth of 12 kilometres, the USGS said.
It measured 6.7 according to the Japan Meteorological Agency, and in some places was as high as a strong six on the agency's seven-point "Shindo", or Seismic Intensity Scale, which measures ground motion at specific points unlike magnitude which expresses the amount of energy released.
Tokyo Electric Power Co's (Tepco) Kashiwazaki-Kariwa nuclear plant was not affected by the quake, which hit 85km north-east of the site. All of its seven reactors were already shut down, NHK said.
A Tepco spokesman said an initial inspection showed no damage to the plant, and inspectors would carry out more detailed checks.
Japan sits on the Pacific "Ring of Fire" where many of the world's earthquakes and volcanic eruptions are recorded.
On March 11, 2011, a devastating 9.0-magnitude quake struck under the Pacific Ocean, and the resulting tsunami caused widespread damage and claimed thousands of lives.