A moderate 5.9-magnitude earthquake struck off Japan on Thursday, US geologists said, close to the area hit by twin disasters in March, but there was no immediate tsunami warning or reports of damage.
The undersea quake hit at 04:24am (1924 GMT) at a depth of 37 kilometres (23 miles), 64 kilometres from Iwaki and 112 kilometres from Sendai, the United States Geological Survey said -- both cities struck by the tsunami that left almost 20,000 dead or missing after a massive 9.0 earthquake in March.
The area is also close to a nuclear plant that was crippled by the March disasters and has since leaked radiation into the air, soil and sea, but has remained stable through a series of more recent tremors.