A series of earthquakes measuring at or above 6 on the Richter scale jolted off Japan's main Honshu island Saturday morning, according to the China Earthquake Network Center.

The strongest quake among them measuring 6.3 on the Richter scale hit off the west of Honshu island at 2:59 a.m., the center said in a statement.

The epicenter, with a depth of 10 km, was monitored at 37 degrees north latitude and 138.5 degrees east longitude, the center said.

A massive 8.8-magnitude earthquake jolted the east coast of Japan's main Honshu Island at 1:46 p.m. Beijing Time Friday, causing hundreds of deaths and severe damage.