6.8 Magnitude Earthquake Strikes Off Japan's Northeast Coast

A strong earthquake measuring 6.8 on the Richter Scale has struck off Japan's northeastern coast, the Japan Meteorological Agency reported Friday.

The agency added that a 50 cm tsunami advisory has been issued for the coast of Miyagi and Fukushima prefectures, the two regions devastated by a massive quake and tsunami in March.

According to the agency, the quake struck at a depth of about 20 kilometers, with its epicenter located slightly south to that of the 9.0 magnitude temblor that struck the region on March 11.

Friday's quake rocked the Miyagi and Fukushima prefectures and the tremor was felt in Capital Tokyo also. Local reports indicated that buildings in Tokyo swayed mildly in the quake.

Earthquakes frequently rock Japan as it sits on top of four tectonic plates. The latest quake comes when Japan is struggling to come to grips with the March 11 catastrophe that killed more than 15,000 people and caused wide-spread devastation.

The March quake and accompanying tsunami had knocked out the cooling systems at the the Fukushima Daiichi civilian nuclear plant, leading to meltdowns and radiation leaks that are yet to be plugged.