No immediate casualties or damage were reported and no tsunami warning was issued.
The quake occurred at 12:01 pm (0301 GMT) with its epicentre off Japan's northern island of Hokkaido at a depth of 590 kilometres, the agency said.
On March 11, 2011, a magnitude-9.0 quake and tsunami hit north-eastern Japan, leaving nearly 19,000 people dead or missing.//DPA