TOKYO June 23 AP - A strong earthquake has struck off an island chain south of Tokyo, but there is no danger of a tsunami, officials say.
Japan's Meteorological Agency said on Tuesday the earthquake measured a preliminary magnitude of 6.9 and was very deep, about 480km below the ocean's surface.
The US Geological Survey put the magnitude at 6.3.
The Japanese agency said the quake was centred west of the Ogasawara island chain in the Pacific Ocean about 1000km south of Tokyo.
Some islands in the chain were shaken strongly by the quake, but it was hardly felt in Tokyo.
The area was also struck by another extremely deep earthquake on May 31, which also did not trigger a tsunami.
Japan sits along the Pacific "Ring of Fire," the arc of seismic faults around the Pacific Ocean where earthquakes and volcanoes are common.
