TOKYO (AFP) — A powerful magnitude 7.1 earthquake struck southwestern Japan on Tuesday, triggering a tsunami alert and shaking parts of Kyushu with the strongest intensity on the country’s seismic scale.

The quake hit at 4:27 p.m. and registered the maximum level 7 on Japan’s Shindo intensity scale, the Japan Meteorological Agency said. Authorities warned that tsunami waves of up to 1 meter (3 feet) could reach coastal areas around 5 p.m., while public broadcaster NHK reported that waves of that height may already have been observed.

There were no immediate reports of casualties or major damage.

Japan is one of the world’s most earthquake-prone countries, sitting atop four major tectonic plates along the Pacific “Ring of Fire” and accounting for about 18 percent of the world’s earthquakes.

The latest quake follows a magnitude 7.2 earthquake in northern Japan in June that caused no major damage and comes months after a magnitude 7.7 quake in April injured at least 10 people and prompted a weeklong advisory warning of an elevated risk of a much stronger earthquake.

Japan remains haunted by the March 2011 magnitude 9.0 earthquake and tsunami that killed or left missing about 18,500 people and triggered the Fukushima nuclear disaster.