TOKYO: An earthquake with a preliminary magnitude of 6.8 struck Japan's northwest coast around Niigata prefecture on Tuesday (Jun 18), triggering a small tsunami, shaking buildings and cutting power to around 9,000 buildings.
The quake, which hit 85km northeast of the island of Honshu, struck at 10.22pm local time (9.22pm Singapore time) at a shallow depth of 10km. Shallow quakes typically cause more damage.
The US Geological Survey put the magnitude of the quake at 6.4.
Japan's Meteorological Agency issued a warning for a 0.2m to 1m tsunami along the north west coast of the main island.
The warning was lifted hours later at 1.02am local time after only small ripples of 10cm were monitored on the coast of the Sea of Japan, north of Tokyo.
An official of the disaster management office of Niigata prefecture told AFP: "We do not have a precise picture of the impact as we are still collecting information."
At least 16 were injured after the earthquake, local authorities told AFP.
In Niigata, a man in his 30s fell down and broke a bone, a woman in her 60s fell from her wheelchair and sustained light injuries, and two others were also lightly injured, the prefecture's disaster management department said in a statement.
In Yamagata, at least 12 people were injured "but we are still gathering information on details," the prefecture's disaster management official Yusuke Niizeki told AFP.
Separately, a fire department official in the region said two elderly women were sent to hospital following falls but "they were conscious".
Witnesses cited by national broadcaster NHK said they experienced strong shaking that knocked some books off shelves and moved some furniture.
The broadcaster showed images of some cups and glasses smashed on the floor of a restaurant.
Bullet train services were immediately stopped by officials after the quake in the region as a precautionary measure, according to NHK.
Some local roads were also closed after the earthquake.
Tokyo Electric Power's Kashiwazaki-Kariwa nuclear plant was not affected by the quake, with all of its seven reactors already shut down, NHK said.
"All nuclear power plants have reported no abnormalities," government spokesman Yoshihide Suga told reporters.
"Strong jolts may continue."
Japan sits on the Pacific Ring of Fire where many of the world's earthquakes and volcanic eruptions are recorded.
Last June, a deadly tremor rocked the Osaka region, killing five people and injuring more than 350.
On Mar 11, 2011, a devastating 9-magnitude quake struck under the Pacific Ocean, and the resulting tsunami caused widespread damage and claimed thousands of lives.
Niigata itself has a history of large earthquakes.
In 2004 a 6.8-magnitude quake hit, killing 68 people, including the elderly who died in the days and weeks after the first tremor from stress and fatigue.
The area was also hit by another 6.8-magnitude quake in 2007, leaving 15 people dead.