TOKYO (Kyodo) -- A magnitude-6.3 earthquake struck eastern and northeastern Japan on Wednesday night, briefly disrupting railway operations, and the temblor was felt in Tokyo, but no tsunami warning was issued.
The quake occurred at 9:38 p.m. in northern Ibaraki Prefecture in eastern Japan and originated at a depth of around 10 kilometers, the Japan Meteorological Agency said.
A woman in her 40s sustained a minor injury when she fell in her home in Kitaibaraki, Ibaraki Prefecture, as the quake hit the area, according to local firefighters. A man in his 60s was also slightly injured by a falling object in Takahagi, Ibaraki.
The Japan Atomic Power Co. said no abnormality was found at the Tokai No. 2 nuclear power plant in the prefecture northeast of Tokyo.
No abnormalities were likewise detected at two nuclear power plants -- the crippled Fukushima Daiichi and idled Fukushima Daini -- in Fukushima Prefecture, north of Ibaraki, according to the operator, Tokyo Electric Power Company Holdings Inc.
No abnormality was observed at the Onagawa nuclear power plant in Miyagi Prefecture in the country's northeast.
The quake, which measured lower 6 on the Japanese seismic scale of 7 -- is likely one of the aftershocks of the magnitude-9.0 mega quake in March 2011 that devastated northeastern Japan with ensuing massive tsunami, according to the weather agency.
Prime Minister Shinzo Abe, who returned home just a few hours before the quake after visiting Pearl Harbor in Hawaii, instructed relevant ministers and agencies to ascertain the extent of the damage.
Chief Cabinet Secretary Yoshihide Suga said at a press conference late Wednesday that there are no reports yet of damage from the quake.
Railway operators said train services on the Tohoku and Tokaido shinkansen lines were briefly halted by the quake, which was also felt in the capital and its vicinity.
Some parts of the Joban Expressway were briefly closed to vehicle traffic, East Nippon Expressway Co. said.