A 5.9 magnitude earthquake has struck Aomori and Iwate prefectures in northern Japan causing apparently minor damage, the country's Meteorological Agency says.
The quake struck at around 2.46am local time on Wednesday (4.46am AEDT) and did not cause a tsunami, the agency said.
No damage was reported at a nuclear fuel pre-processing plant in the area, public broadcaster NHK said.
Two people were injured and taken to hospital, while train operators in the area suspended some services for safety checks, the broadcaster said.
The quake registered five-plus on the Japanese scale of earthquake intensity, a level that could cause damage to some buildings.