An earthquake with a magnitude of 6.6 rattled southwestern and western Japan early Saturday, resulting in at least nine injuries amid strong shaking although no tsunami waves were triggered, the weather agency and local authorities said.

The focus of the quake under the Pacific Ocean was within a zone off Japan's coast where an earthquake causing a massive tsunami is predicted to occur in the future. The Meteorological Agency said it will study whether the latest quake is connected in any way with the one feared to be coming.

The quake occurred at around 1:08 a.m., logging an upper 5 on the Japanese seismic intensity scale of 7 in Miyazaki and Oita prefectures on the country's southwestern main island of Kyushu, the weather agency said.