TOKYO, Japan (AFP)— A powerful earthquake with a magnitude of 7.1 shook southern Japan on Thursday but no major damage was reported and only relatively minor tsunami waves lashed the coast.

The quake hit at 4:42 pm (0742 GMT) off the southern island of Kyushu at a depth of 25 kilometres (16 miles), the United States Geological Survey (USGS) said.

The USGS had initially reported two strong quakes, with magnitudes of 6.9 and 7.1, but later said there had only been one tremor.

The Japan Meteorological Agency (JMA) also said there was one quake with a magnitude of 7.1.

Broadcaster NHK showed footage of traffic lights shaking violently in Miyazaki on Kyushu’s southeast coast.

“The surface of the sea is wavering. I felt an intense jolt when the quake happened which lasted for between 30 seconds and a minute,” one local official told NHK.

Government spokesman Yoshimasa Hayashi said officials were notified of one minor injury and two other unspecified injuries.

No disruptions to infrastructure, including electricity, water and telecommunications, were reported, Hayashi added.

Unverified footage shared on social media showed only minor damage, including dishes and books that had fallen off shelves and a small wall that had collapsed in a car park.

Tsunamis of up to one metre were initially expected to arrive or had arrived in some coastal areas in Kyushu and Shikoku islands, the JMA said.

The agency also said a small tsunami was possible in Chiba, about 850 kilometres (530 miles) from the epicentre.

“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 platform X.

However, tsunamis of only 50 centimetres (20 inches), 20 centimetres and 10 centimetres were confirmed to have hit some places, including the port of Miyazaki, more than an hour after the quake, it said.

The Pacific Tsunami Warning Center issued a warning that said hazardous tsunami waves were possible within 300 kilometres (185 miles) of the epicentre.

No abnormalities were reported at atomic power plants in the area, according to the nuclear regulation authority.

The Japanese government set up a special task force in response to the quakes, according to a statement.

Sitting on top of four major tectonic plates along the western edge of the Pacific “Ring of Fire”, Japan is one of the world’s most tectonically active countries.