A strong earthquake with a preliminary magnitude of 7.4 on the Richter scale shook northeastern Japan, including Fukushima Prefecture, on Thursday, the Japan Meteorological Agency said. The US Geogolical survey has lowered the earthquake to 7.1.
There were no immediate reports of injuries caused by the 11:32 p.m. (1432 GMT) quake.
The agency issued a tsunami warning for waves up to one meter high along Japan’s northeastern Pacific coast.
The crippled Fukushima Daiichi nuclear power plant was not further damaged by Thursday’s quake, the plant operator said.
The Fukushima complex has continued to leak radioactive substances since the March 11 disasters.
The focus of the tremor was off the coast of Miyagi Prefecture at a depth of about 40 km, the weather agency said.
The quake registered upper 6 on the Japanese seismic scale of 7 in some parts of Miyagi Prefecture, about 300 km north of Tokyo.
The agency defines an intensity of upper 6 as strong enough to make most heavy and unbolted furniture moves and falls.
The Japanese scale measures how much places were shaken on the surface while the Richter scale measures the energy of the quake itself.
Northeastern Japan was already severely damaged on March 11 by a magnitude 9.0-quake and tsunami that left about 28,000 people dead or missing.
Earlier this week, the weather agency urged people in the region to continue to be alert against powerful aftershocks.