A 7.4-magnitude earthquake has struck in the Pacific Ocean off southern Japan, the US Geological Survey (USGS) says.

美国地质勘探局称，日本南部太平洋海域发生7.4级地震。

The epicentre of the earthquake was 155km (95 miles) off the Bonin Islands, some 1,000km south-east of Tokyo, the USGS said.

It struck at a depth of some 15km at 0220 (1720GMT), sparking local tsunami¹ warnings which were later lifted.

Japan is well-prepared for quakes which often hit the seismically²（地震） active area.

In 1995, a magnitude-7.2 quake in the port city of Kobe killed 6,400 people.

There were no reports of casualties（人员伤亡） or damage from the latest earthquake.

Local TV broadcasts warned coastal³ inhabitants to seek safety on higher ground, but the quake only prompted a swelling⁴（肿胀，膨胀） of waves around 30cm (1ft) high.

Known in Japan as the Ogasawara Group, the Bonin archipelago（群岛，列岛） comprises some 30 tropical or sub-tropical islands, only two of which are populated.

They are inhabited by around 2,500 people.