A 5.7 magnitude earthquake hit Japan's southern Okinawa island and a chain of neighbouring islands on Monday, but no tsunami alert was issued.
Authorities said there were no immediate reports of any damage or injury.
Japan is situated at the junction of four tectonic plates and hence it experiences a number of relatively violent quakes every year.
Japan accounts for about 20 per cent of the world's earthquakes of magnitude 6 or greater.
On March 11, 2011, the north-east coast of Japan was struck by a magnitude 9 earthquake which was the strongest quake in Japan on record and triggered a massive tsunami.
