A 5.8 magnitude earthquake hit northeast of Tokyo off Japan's main island of Honshu on Thursday, the Pacific Tsunami Warning Center (PTWC) and the USGS said. Local police said there were no immediate reports of damage or injuries.
The USGS said that the quake struck at a depth of 33 km about 79 km east-northeast of Iwaki on Honshu at 9.11am (8.11am, Singapore time). However, Hawaii-based PTWC did not issue any immediate tsunami warning.
Japan's meteorological agency said that there was no risk of tsunami from the earthquake. "We have found no (new) abnormality so far" at the Fukushima Daiichi plant, a spokesman at Tokyo Electric Power Co., the operator said.
Japan is located at the junction of four tectonic plates and earthquakes are quite common in the country. The country sits on one of the world's most seismically active zone known as the Pacific Ring. But rigid building codes and strict enforcement mean even strong tremors often do little damage.
Reports say Japan accounts for about 20 percent of the world's earthquakes of magnitude-6 or greater. On March 11, 2011, the north-east coast was struck by a magnitude 9 earthquake, the strongest quake in Japan on record, and a massive tsunami.
Tokyo Electric is working to clean up and dismantle the reactors in a process that is expected to take at least four decades.