An earthquake with a preliminary magnitude of 5.0 jolted northern Japan on Sunday, but there were no immediate reports of injuries or damage. No tsunami warning was issued after the quake, which occurred at 11:29 am (0229 GMT), the Meteorological Agency said.
The focus of the tremor was very shallow in Niigata prefecture, the agency said.
A local official said the quake caused a brief scare.
"We were surprised initially because it shook pretty much," Hiroyuki Murayama, an official at Nagaoka city said on public broadcaster NHK.
"It caused papers and tableware to become cluttered... But so far there are no reports of any major damage," he added.
The superfast bullet train system was stopped briefly when the quake caused electricity to be cut off, but resumed operations minutes later, NHK said. Parts of an expressway were also closed off after the tremor.
No irregularities were found at a nuclear plant at Kashiwazaki in Niigata after the quake, NHK said.
The magnitude of the earthquakes was measured according to a technique similar to the Richter scale, but adjusted for Japan's geological characteristics.
Earthquakes are common in Japan, one of the world's most seismically active areas. The country accounts for about 20 percent of the world's earthquakes of magnitude 6 or greater.
The latest quake struck less than a week after a major earthquake with a magnitude of 7.2 jolted another area of northern Japan on Tuesday. One media report said at least 67 people were injured in that quake, which caused power outages and brought trains to a halt.
In October 2004, an earthquake with a magnitude of 6.8 struck the Niigata region in northern Japan, killing 40 people and injuring more than 3,000.