A Tsunami advisory was issued in the wake of a powerful earthquake off Japan's southern coast on Thursday. Though there were no immediate reports of injuries or serious damage, residents have been urged to stay away from the coastline.

According to the Japan Meteorological Agency, the earthquake measured 7.1 magnitude and was centered in waters off the eastern coast of Japan's southern main island of Kyushu at a depth of around 30 kilometers.

Tremors were most strongly felt in Nichinan city and the nearby areas in Miyazaki prefecture on Kyushu island.

Tsunami waves of up to 50 centimeters were detected along parts of Kyushu's southern coast and the nearby island of Shikoku about half an hour after the earthquake struck, the agency mentioned.

An emergency meeting was held by seismologists to analyse whether the earthquake had affected the nearby Nankai Trough, the source of past devastating earthquakes.

Officials have been assessing the possible injuries or serious damage, said Yoshimasa Hayashi, chief cabinet secretary. He urged residents of the affected region to move away from the coastline.

There were reports of broken windows at the Miyazaki airport near the epicenter, as televised by Japan's NHK public television. All 12 nuclear reactors including three which are currently operating, on Kyushu and Shikoku are safe, as per the Nuclear Regulation Authority.

Notably, a tsunami followed a massive earthquake in March 2011 trigger the Fukushima nuclear disaster. Since then, earthquakes in the areas with nuclear power plants have been a major concern.

Japan sits on the Pacific 'Ring of Fire', the line of seismic faults that encircles the Pacific Ocean. It is one the world's most earthquake-prone countries in the world.