A powerful earthquake has struck off the coast of Japan, but no tsunami warnings were issued.

The U.S. Geological Survey says a 6.6. magnitude quake struck early Saturday about 125 kilometers off the east cost of Honshu island.

Reports from Japan say there is no risk of a tsunami. There were no immediate reports of damage or injuries.

A massive earthquake and tsunami devastated northeast Japan in March, leaving nearly 20,000 people dead or missing and triggering a meltdown at Fukushima Daiichi nuclear power plant.

There have been a series of earthquakes of a lesser magnitude since the March quake.