“Many people” were trapped inside a shopping centre damaged in a major earthquake in southwestern Japan, emergency services said.

In “Kashima town, a shopping complex’s second floor collapsed, leaving many people trapped inside,” the fire department said in a statement.

Broadcaster TBS said that a “considerable” number of people in the shopping centre had died following the earthquake.

Police told AFP that they could not confirm whether there were any fatalities at the shopping centre in the town of Kashima.

Earlier, police said they had received reports of what sounded like an explosion at the Aeon shopping outlet in the Kumamoto region, with no information on damage or any casualties.

An Aeon spokesperson said customers and employees were evacuated right after the initial quake and that the exact cause of the ensuing explosion was unclear.

Kazuya Tsurunaga told TBS he heard the explosion while cleaning up dishes broken by the earthquake inside a pub about 300 metres from the Aeon shopping centre.

“It was a huge impact,” he said.

“A large cloud of smoke billowed up, and because the wind happened to be blowing and the wind direction was towards the ‌shop, the area around us was in a state like volcanic ash was falling.”

Screengrab handout from Japan's Ministry of Defence of a building with smoke rising from it after an earthquake in Uki City, Kumamoto Prefecture
Around 300,000 people have been instructed to go to evacuation centres, the disaster management agency said

The earthquake collapsed buildings and sparked fires in Japan’s southwest, Prime Minister Sanae Takaichi said, with broadcaster NHK saying that at least 50 people were taken to hospital.

Television footage on NHK showed several blazes, damaged bridges, a derailed cargo train and cracked roads after the tremor on Kyushu island.

The broadcaster reported at least 12 collapsed houses.

TSMC, the world’s largest contract chipmaker, evacuated workers from its plant in the area as a precaution, a spokesperson for the firm said.

Sony and Fujifilm also evacuated staff from ‌their plants in the area, Nikkei newspaper reported.

A Sony spokesperson earlier said it was checking the situation.

Photo of an overturned train after an earthquake in Japan
The earthquake collapsed buildings and sparked fires in Japan’s southwest

The quake at 4.27pm (08.27 Irish time) had a magnitude of 7.1, according to the Japan Meteorological Agency, but reached the highest possible level of seven on Japan’s Shindo scale of shaking.

The US Geological Survey (USGS) measured the quake – one of hundreds that strike Japan every year – at 6.8. The vast majority cause little damage.

“We are still assessing the extent of injuries and property damage, but I have been informed that there have already been several injuries,” Ms Takaichi said.

“Power outages and fires are happening in some areas, and roads and bridges have been damaged and buildings collapsed,” she said.

Around 300,000 people have been instructed to go to evacuation centres, the disaster management agency said, while Ms Takaichi said 3,600 soldiers would be deployed to help with the disaster recovery as aftershocks continued to rumble.

Watch: Cameras capture violent shaking as 7.1 magnitude tremor hits Japan’s Kyushu island

The JMA initially issued an alert for a possible tsunami of up to one metre, but withdrew the warning at around 6.10pm.

“This earthquake occurred inland, and no tsunami activity has been observed so far. For this reason, we hope to lift the tsunami advisory at a relatively early stage, depending on future sea level conditions,” a Japan Meteorological Agency spokesperson said.

No immediate abnormalities were recorded at nuclear power plants, the Nuclear Regulation Authority said.

The UN nuclear watchdog said that Japan’s nuclear regulation authority has informed it ‌that there is no damage or safety issues at the Sendai nuclear ‌power plant after the 7.1-magnitude ‌earthquake hit Japan’s southern Kumamoto prefecture.

“The ‌IAEA will continue to monitor the situation,” said the watchdog in a post on X.

About 45,000 households and facilities have no power in the Kumamoto region, according to local utility Kyushu Electric Power.

The firm added that three nuclear reactors operating in the region at the time were functioning normally.

An infographic titled '7.1-magnitude earthquake hits Japan' showing the location on a map

‘Shaking is continuing’

A local NHK staffer wearing a helmet reported live on air that the shaking was continuing around half an hour after the quake, with the newsroom rocking so violently that it was difficult to remain standing.

“Shaking is continuing as I speak. Including myself, there may be some people who feel their hearts racing,” the staffer said.

“When the quake struck, the shaking was so big that I could not stand up. Please be aware of possibility that shaking might continue after this.”

Kumamoto was hit by two devastating earthquakes in 2016 – one of magnitude 6.5, followed two days later by one of magnitude 7.3 – which killed 273 people and injured more than 2,800.

A quake with a magnitude of 7.2 hit northern Japan on 25 June but caused no deaths or major damage.

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

People wait in a park after evacuating buildings following a strong earthquake in Kumamoto City
People wait in a park after evacuating buildings following a strong earthquake in Kumamoto City

The archipelago, home to around 125 million people, typically experiences hundreds of jolts every year and accounts for about 18% of the world’s earthquakes.

The vast majority are mild, although the damage they cause varies according to their location and the depth below the Earth’s surface at which they strike.

Japan is haunted by the memory of a massive 9.0-magnitude undersea quake in 2011, which triggered a tsunami that killed or left missing around 18,500 people and wrecked the Fukushima nuclear plant.

A tremor measuring 7.7 hit the country’s north on 20 April this year, injuring at least 10 people and shaking large buildings in Tokyo.

That prompted authorities to issue a special advisory warning of an increased risk of earthquakes of magnitude 8.0 or stronger.

The advisory was lifted after a week.