TOKYO -- A magnitude-6.2 earthquake struck off the east coast of Japan early Saturday, but no damage or casualties were reported.

The U.S. Geological Survey said the quake hit 12 kilometres from Onagawa near Sendai at 6:42 a.m. No tsunami warning was issued.

The temblor's epicenter was at a depth of 45 kilometres, the USGS reported.

Japan, which sits along the Pacific "Ring of Fire," is one of the world's most earthquake-prone countries.