A 6.8-magnitude earthquake hit southern Japan on Tuesday, killing at least 13 people and injuring hundreds as a massive search remains underway to rescue those trapped under rubble.
The earthquake – estimated at 6.8 by the US Geological Survey and 7.1 by the Japan Meteorological Agency – hit inland on Kyushu island with its epicentre in Kumamoto Prefecture at 4.27 local time on Tuesday.
The earthquake prompted a tsunami warning for waves as high as 3ft, which was lifted two hours later.
USGS initially measured the quake at 7.1 but revised it to 6.8. However, the JMA said it had a magnitude of 7.1 and reached the highest level of 7 on Japan’s own shindo scale.
Prime minister Sanae Takaichi said rescue teams were racing against time as saving the lives of people was the top priority.
"There are people who are still waiting to be rescued, and it's a race against time," Ms Takaichi said on Wednesday. "We will go all out to find and rescue as many people as we can."
The earthquake left a trail of destruction, with collapsed buildings, buckled roads and rescue teams combing through piles of rubble.
One of the worst-hit sites was the Aeon shopping mall in Kumamoto, where rescuers pulled eight people from the rubble after part of the building collapsed. Two women in their 20s were killed when an explosion of unknown origin tore through the mall about an hour after the earthquake. Authorities are investigating whether a gas leak triggered the blast.
One side of the shopping centre, home to around 200 stores, was ripped away, exposing steel beams and scattering debris across a vast parking lot.
Around 300,000 people were ordered to evacuate, while residents were warned to brace for further strong aftershocks and possible landslides over the coming week. By Wednesday morning, authorities had recorded more than 170 aftershocks, according to NHK.
The Japanese military deployed 3,600 personnel and 20 aircraft for disaster relief operations, while hundreds of firefighters and rescue workers from neighbouring prefectures were sent to Kumamoto to assist with search efforts.
Nearly 50,000 households remained without electricity late on Tuesday, while around 140,000 were without running water. Temperatures were forecast to exceed 35C (95F) on Wednesday, raising concerns about heatstroke for residents without power or air conditioning. Many people spent the night sleeping in their cars for fear of further aftershocks.
Several ambulances and fire engines were stationed outside the damaged mall as rescue teams searched for survivors. Aeon said customers and employees had been evacuated immediately after the initial quake and that the cause of the subsequent explosion remained unclear.
Witness Kazuya Tsurunaga told TBS he was cleaning up broken dishes inside a pub about 300m from the mall when the blast occurred.
"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."
Multiple people were also unaccounted for after a chimney collapsed at a Nippon Paper Industries factory, NHK reported.
Rail transport was severely disrupted after the earthquake, with JR Kyushu suspending train services, including its high-speed Shinkansen bullet trains. Kumamoto Airport also closed its runway, forcing airlines to divert or cancel flights.
Some roads were also badly damaged, with large cracks splintering major highways, snarling traffic.
TSMC, the world's largest contract chipmaker, Sony and Fujifilm evacuated workers from their plants following the quake. TSMC said in a statement late Tuesday that its site was unaffected and operations were gradually resuming.
The epicentre of the earthquake was 20km south of Kumamoto, central Kyushu island’s largest city, which has a population of 700,000 people. A subsequent aftershock with a magnitude of 6.1 was registered shortly after at 5.08pm.
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.
A massive earthquake in Kumamoto 10 years ago killed 275 people and injured a further 2,739, according to an official count. The 2016 disaster damaged thousands of buildings, including the walls of the city's castle, a top tourist site.
