The quake, with its epicenter some 350 kilometers (220 miles) northeast of Tokyo in the Pacific Ocean and 30 kilometers below sea level, occurred at 11:58 am (0258 GMT), the agency said.

No tidal wave warning was issued and there were no immediate reports of casualties or damage.

A smaller quake, measuring 4.7 on the Richter scale, occurred at 1:09 pm Sunday, near the eastern tip of Japan's northern island of Hokkaido.

TERRA.WIRE