6.1 magnitude earthquake strikes in sea off Japan

(CNN) -- A 6.1 magnitude earthquake struck early Friday in the sea that separates three of Japan's main islands, about 100 miles southwest of Hiroshima, the Japan Meteorological Agency said.

2011: Moment of the Japan quake

The quake happened at 2:07 a.m. and was centered in the Inland Sea at a depth of 80 kilometers, the agency said.

The earthquake posed no tsunami risk, according to the agency.

The Inland Sea separates Japan's largest island, Honshu, from the southern islands of Shikoku and Kyushu.