A strong 6.0-magnitude earthquake struck off Japan's southern island of Okinawa early Friday, the US Geological Survey said.
The quake struck at 4:19 am (1919 GMT Thursday), 165 kilometres (105 miles) northwest of Okinawa's capital Naha at a depth of 138 kilometres, according to the USGS.
There were no immediate reports of casualties or damage.
Around 20 percent of the world's most powerful earthquakes strike Japan.
Share This Article With Planet Earth