Strong 7.1 magnitude earthquake off southern Japan prompts tsunami advisory

A powerful earthquake struck off Japan's southern coast on Thursday, triggering a tsunami advisory. There were no immediate reports of casualties, the Reuters news agency reports.

The Japan Meteorological Agency said the quake, which hit at 4:43 p.m. local time, registered magnitude 7.1 and was centered off Miyazaki prefecture of the western major island of Kyushu. It stuck at a depth of about 18.6 miles.

The agency issued a tsunami advisory, predicting waves of up to 3.3 feet along the southern coast of Kyushu and nearby island of Shikoku.

"Tsunamis will strike repeatedly. Please do not enter the sea or approach the coast until the warning is lifted," the JMA said on social media, according to the AFP news agency.

Waves as high as 20 inches have already been observed in Miyazaki, public broadcaster NHK said, according to Reuters.

Chief Cabinet Secretary Yoshimasa Hayashi told reporters there weren't any reports of abnormalities at nuclear power plants following the quake, and the government was checking for damage and casualties, Reuters reported.

Japan's NHK public television said there were reports of broken windows at the Miyazaki airport near the epicenter.

The United States Geological Survey gave the earthquake a yellow alert for estimated economic losses, meaning "some damage is possible and the impact should be relatively localized." It gave the quake a green alert for estimated fatalities, meaning "there is a low likelihood of [shaking-related] casualties."

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 on Jan. 1 in Japan's north-central regio n of Noto left more than 240 people dead.