Companies including Sony 6758.T and TSMC 2330.TW, the worldâs largest contract chipmaker, have plants in the area of the quake.

A Sony spokesperson said the company was checking the situation. TSMC did not immediately respond to a request for comment.

The Japanese government issued emergency earthquake warnings for Kumamoto, Nagasaki, Kagoshima, Fukuoka, Saga, Oita, and Miyazaki prefectures, all on Japanâs southern Kyushu island. A tsunami warning for a wave measuring 1 m (3.28 feet) was issued after the earthquake, the Japan Meteorological Agency said.

Japan is one of the worldâs most earthquake-prone countries, with a tremor occurring at least every five minutes. Located along the âRing of Fireâ of volcanoes and oceanic trenches partly encircling the Pacific Basin, Japan accounts for about 20% of the worldâs earthquakes of magnitude 6.0 or more.

A massive earthquake in Kumamoto 10 years ago killed 275 people and injured a further 2,739, according to an official count.

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, Japanâs nuclear regulation authority said.

(Reporting by Anton Bridge, Kantaro Komiya, Mariko Katsumura and Hina Suzuki; Writing by John Geddie; Editing by Chang-Ran Kim and Kate Mayberry)