Powerful earthquakes struck Japan, Mexico and China within hours of one another on Tuesday, prompting a tsunami warning in southern Japan and emergency responses in parts of Asia.

The strongest of the earthquakes, with a preliminary magnitude of 7.1, struck Japan’s Kumamoto prefecture, according to the Japan Meteorological Agency (JMA).

A tsunami warning for waves of up to 1 metre (3.3 feet) was issued following the earthquake.

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

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% of the world’s earthquakes of magnitude 6.0 or more.

Kyushu Electric Power said there were no reports of irregularities at its Sendai and Genkai nuclear power stations after the earthquake.

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

There were no immediate details about casualties or damage.

In Mexico, a magnitude 5.8 earthquake struck near the coast of Puerto Madero early on Tuesday, according to the United States Geological Survey.

The earthquake occurred at a depth of 35km (21.7 miles). No immediate reports of casualties or damage were available.

Meanwhile, two earthquakes struck the remote county of Xinghai in China’s northwestern Qinghai province within 18 minutes of each other.

The first, measuring magnitude 5.7, struck at 11.16am local time (0316 GMT), according to the China Earthquake Networks Centre. A second earthquake of magnitude 5.8 followed at 11.34am.

Both earthquakes occurred at a depth of 10km (6.2 miles). Their epicentres were located in a sparsely populated, high-altitude area approximately 244km (152 miles) from Xining, the provincial capital.

Tremors were felt in Xining, China’s state-run Xinhua news agency reported.

Authorities had received no reports of casualties or collapsed buildings, while public order remained stable, Xinhua said. Emergency response teams were travelling to the epicentral area to assess conditions.

There was no immediate indication that the earthquakes in Japan, Mexico and China were connected. Earthquakes occurring in different parts of the world within a relatively short period do not necessarily share a geological cause.