An aftershock measuring up to a lower 5 on the Japanese seismic intensity scale struck the same area about 30 minutes later, prompting authorities to urge residents to remain alert for additional strong tremors, The Japan Times reported.

According to the newspaper, the earthquake's epicentre was located in the city of Uki, just south of Kumamoto City, at a depth of 10 kilometres.

Local media reported that several buildings collapsed near the epicentre, while the fire department said it received multiple emergency calls following the quake.

The Japan Meteorological Agency issued a tsunami warning for the affected region shortly after the earthquake.

No casualties have been reported so far, while the full extent of the damage is yet to be determined.

In a post on X, Japanese Prime Minister Sanae Takaichi urged residents in the affected areas to remain vigilant.

"To those in the areas where the shaking was strong, I would like to ask you to continue to be vigilant against the occurrence of earthquakes of the same magnitude," she said.

Japan, located along the seismically active "Ring of Fire"—a belt of volcanoes and oceanic trenches encircling much of the Pacific Ocean—is among the world's most earthquake-prone countries.

In 2016, the Kumamoto region was devastated by a series of powerful earthquakes that claimed at least 276 lives and caused widespread destruction.