A strong earthquake with a preliminary magnitude of 6.9 rocked Japan's Tokaido Nampo-oki region Sunday, the Japan Meteorological Agency said.

The focus of the quake, which occurred at 07:56 p.m. local time (1056 GMT), was some 340 km under the surface of the sea off the Tokaido area, the agency said.

There were no immediate reports of casualties or damage to properties, and no tsunami warning was issued.

(Xinhua News Agency August 10, 2009)