A powerful 7.1-magnitude earthquake has struck Japan, triggering tsunami warnings and shaking neighbouring countries.

The quake struck at 4.28pm local time (5.28pm AEST) on Tuesday at a depth of 10km at Japan’s southwestern Kumamoto Prefecture, according to the US Geological Survey.

The Japanese government issued emergency earthquake warnings for Kumamoto, Nagasaki, Kagoshima, Fukuoka, Saga, Oita, and Miyazaki prefectures, all on Japan’s southern Kyushu island.

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Australia’s Bureau of Meteorology said there was no tsunami threat to the Australian mainland, islands or territories.

Meanwhile, a separate 5.0-magnitude earthquake struck China’s Qinghai Province at 4.04pm local time (6.04pm AEST), about 995km from Kumamoto, according to China Earthquake Networks Centre.

The quake occurred at a depth of 10km too.

Japan is one of the world’s most earthquake-prone countries, with a tremor occurring at least every five minutes.

Located along the “Ring of Fire” of volcanoes and oceanic trenches partly encircling the Pacific Basin, Japan accounts for about 20 per cent of the world’s earthquakes of magnitude 6.0 or more.

Kyushu Electric Power said about ⁠40,000 homes had lost power as a result of the quake, while railway company JR Kyushu said ⁠that it ‌had suspended services, including its high-speed bullet trains.

There were no irregularities reported at the nuclear ‌power stations ‌in the ​area, ​Japan’s nuclear regulation authority said.

Train operator JR Kyushu said it had suspended services, including its high-speed Shinkansen trains following the quake.

- with AAP