Japan's Meteorology Agency was monitoring for the possibility of a tsunami after a volcano erupted in Indonesia on Sunday, public broad caster NHK reported.
A tsunami from the eruption, which occurred around 11:18 a.m. Japan time (0218 GMT), could reach Okinawa Prefecture as early as 0530 GMT, NHK quoted the agency as saying.
(Reporting by Tetsushi Kajimoto; Editing by William Mallard)