An earthquake with a preliminary magnitude of 6.8 has rattled northeast Japan, one of the areas devastated by the March 11 quake and tsunami.
The quake struck off the coast of Iwate prefecture at 6:50am on Thursday (2150 GMT Wednesday), but there were no immediate reports of damage or injuries. The quake was followed shortly after by a magnitude 6.7 tremor.
Al Jazeera's Step Vaessen, reporting from Tokyo, the capital, said a tsunami advisory, issued by the Japan Meteorological Agency, had been lifted.
"There is no tsunami warning at the moment, but the quake has been felt very strongly. People living here off the main Island of Honshu are so much better prepared for earthquakes, there was no panic at all," she said.
The Pacific Tsunami Warning Centre has not issued any warnings or watches for the area, But authorities warned residents to be wary of mudslides.
The earthquake was in the same area of the Pacific where a magnitude-9.0 earthquake struck northern Japan on March 11, triggering a deadly and destructive tsunami which left some 23,000 people dead or missing.
The focus of the tremor was 20km below the seabed off Iwate and about 500km northeast of Tokyo, the Japan Meteorological Agency said.
Tokyo Electric Power Co, struggling to control radiation leaks at its Fukushima Daiichi nuclear plant due to damage in the March disaster, said there was no impact from Thursday's quake on its efforts to bring the reactors under control.
Hundreds of thousands of residents have been forced to leave their homes in the vicinity of the plant in the world's worst nuclear disaster since Chernobyl in 1986.
The Nuclear and Industrial Safety Agency said there were no reports of abnormalities at Tohoku Electric Power's Higashidori and Onagawa nuclear power plants in northeast Japan. Operations of these reactors have been halted since the March disaster.