Tokyo: An earthquake with a preliminary magnitude of 4.6 has shaken eastern Japan, the Japan Meteorological Agency says.
The epicentre of the quake, which hit at 9.27am (local time) on Thursday, was north of Tokyo in the Saitama prefecture, the agency said. The quake was measured at a depth of 50kilometres.
No tsunami warning was issued and there were no immediate reports of damage.
Earlier, a massive earthquake of 8.0 magnitude was detected off the coast of southern Mexico, the US Geological Survey said. Widespread, hazardous tsunami waves were possible, the Pacific Tsunami Warning Centre said.