A moderate 5.7-magnitude earthquake hit Japan's remote Volcano Islands today, seismologists said, although there was no tsunami warning and no immediate reports of damage or injuries.
The quake hit at 5:26 am (local time), 86 kilometres south-east of Iwo Jima, at a depth of 138 kilometres, the US Geological Survey said. The southern chain consists of three small thinly populated volcanic islands. Iwo Jima, the largest, was converted into a military airfield during World War II and was the scene of a bloody battle between Japanese and US forces.
Around 20 per cent of the world's most powerful earthquakes strike Japan, which sits on the "Ring of Fire" surrounding the Pacific Ocean.
But high building standards, regular drills and a sophisticated tsunami warning systems mean that casualties are often minimal. However 17 people were injured in a 7.1-magnitude quake that struck Hokkaido in 2004, a month after a quake measuring 6.8 killed 40 people in the central region of Niigata.