Thousands of personnel have been deployed for search-and-rescue operations. Many are digging through rubble at Kashima’s Aeon shopping centre, one of the worst-hit buildings where a portion of the second floor collapsed.
The mall was also rocked by an explosion about an hour after the initial quake.
The president of Aeon said it was “very likely” a gas explosion, though the cause of the blast remains under investigation.
A cat cafe inside the mall said on Wednesday that its 25 cats, which had been left behind during the chaos of the quake, had all since been safely rescued.
The quake-hit Aeon mall in Kumamoto had just reopened last month as a revamped shopping complex. It had previously been damaged during a series of strong earthquakes in April 2016, which killed 278 people in the region.
Rescuers were also combing a Nippon Paper factory in Yatsushiro city, where at least five people have died after the factory partially collapsed during the quake.
Eleven people were trapped in the building, seven of whom have been rescued so far, Nippon Paper said in a statement on Wednesday.
The quake, which had a shallow depth of 10km (six miles), shocked residents across Kumamoto.
Hiroko Ogata, a 75-year-old restaurant owner in the city of Yatsushiro, told the BBC she hid under a table at her restaurant when the quake struck and swayed violently along with it.
“I have lived here for 75 years, but I have never experienced such a big quake,” she said. “I thought I would die.”
