TOKYO - A magnitude 7.3 quake hit Japan's southern island of Okinawa early on Saturday, the U.S. Geological Survey reported, and Japan's weather agency issued a tsunami warning for up to 2 meters.

The USGS said the quake struck at 5:31 a.m. on Saturday (2031 GMT on Friday) 52 miles east of the city of Naha, about 1,600 km (1,000 miles) south of Tokyo.

The Japan Meteorological Agency put the magnitude at 6.9.

Earthquakes are common in Japan, one of the world's most seismically active areas. The country accounts for about 20 percent of the world's earthquakes of magnitude 6 or greater.

In October 2004, an earthquake with a magnitude of 6.8 struck the Niigata region in northern Japan, killing 65 people and injuring more than 3,000.

That was the deadliest quake since a magnitude 7.3 tremor hit the city of Kobe in 1995, killing more than 6,400.

(Editing by Charles Dick)