A strong earthquake hit off Japan's southern coast on Thursday evening, 8 August, prompting a tsunami advisory.

Authorities in areas of south and central Japan on the Pacific coast advised residents to avoid the coastline, though there were no immediate reports of injuries or significant damage.

The Japan Meteorological Agency in Tokyo reported that the quake, which occurred at 4:43 p.m. local time, had a magnitude of 7.1. It was centred in waters off the eastern coast of Kyushu, Japan's main southern island in the archipelago, at a depth of about 30 kilometres.

Nichinan city and surrounding areas in Miyazaki Prefecture on Kyushu experienced the strongest tremors.

The agency further said that a 50cm tsunami had already been seen along the southern coast of Kyushu and further east on the nearby island of Shikoku approximately half an hour after the earthquake.

Japan’s Chief Cabinet Secretary Yoshimasa Hayashi stated that officials were evaluating potential injuries or damage, but none were immediately reported. He urged residents in the affected region to remain away from the coast.

Shigeki Aoki, an official from the Seismology Department was reported as cautioning that strong aftershocks could occur over the next week by the Associated Press.

NHK public television meanwhile carried stories of shattered windows at Miyazaki airport, not far from the earthquake's epicentre.

NHK also broadcast images of dozens of people gathering at a designated hilltop evacuation site; thousands who failed to act in a similar manner in the 2011 M9.0-9.1 Fukushima earthquake perished in the resulting tsunami in what was the largest earthquake in living memory to hit Japan.

Further south, in Osaki, Kagoshima prefecture, concrete walls collapsed, and a wooden house was damaged, but no injuries were reported.

The Nuclear Regulation Authority confirmed that all 12 nuclear reactors on Kyushu and Shikoku, including three currently operational, remained safe.

Japan, like Taiwan, the Philippines and Indonesia in Asia, is located on the Pacific Ring of Fire and is prone to earthquakes due to its position along a series of seismic faults encircling the Pacific Ocean.