Japan issues tsunami warning after magnitude 6.8 quake south of Okinawa

TOKYO — Japanese authorities issued a warning for a tsunami of up to 3 feet after a strong earthquake struck in the seas south of Okinawa.

The Japan Meteorological Agency said epicenter of the magnitude 6.8 quake on Monday morning was at a shallow point near the Yonaguni islands.

The tsunami warning remained in force for over an hour after the quake struck, but authorities said it was unclear if a tsunami had hit shores of islands in the area.

Television footage of a nearby island showed calm seas, but residents were warned to stay away from the shore.

The public broadcaster NHK said there were no initial reports of damage.