A powerful earthquake has struck off Japan’s southern coast, triggering a tsunami advisory.

Residents were urged to stay away from the coastline, but there were no immediate reports of injuries or serious damage.

The Japan Meteorological Agency said the quake registered a magnitude of 7.1 and was centred in waters off the eastern coast of Japan’s southern main island of Kyushu at a depth of about 18.6 miles (30km).

The quake most strongly shook Nichinan city and nearby areas in Miyazaki prefecture on Kyushu island.

Japan Earthquake
People gather outside a building following the earthquake in Miyazaki, western Japan (Kyodo News/AP)

The agency said tsunami waves of up 1.6ft (50cm) were detected along parts of Kyushu’s southern coast and the nearby island of Shikoku about half an hour after the quake struck.

Seismologists were holding an emergency meeting to analyse whether the quake had affected the nearby Nankai Trough, the source of past devastating earthquakes.

Chief Cabinet Secretary Yoshimasa Hayashi said officials were assessing possible injuries or serious damage, though none were immediately reported. He urged residents of the affected region to stay away from the coastline.

Japan’s NHK public television said there were reports of broken windows at Miyazaki airport near the epicentre. The airport’s runway was temporarily closed for safety checks.

NHK showed dozens of people gathering at a designated hilltop evacuation area.

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

Japan Earthquake
Police stand outside a damaged building in Miyazaki, western Japan, following the earthquake (Kyodo News/AP)

The Nuclear Regulation Authority said all 12 nuclear reactors, including three which are currently operating, on Kyushu and Shikoku remained safe.

Earthquakes in areas with nuclear power plants have been a major concern since a massive earthquake and tsunami in March 2011 triggered the Fukushima nuclear disaster.

Japan sits on the Pacific Ring of Fire, the line of seismic faults encircling the Pacific Ocean, and is one of the world’s most earthquake-prone countries.

An earthquake in Japan’s north-central region of Noto on January 1 left more than 240 people dead.