Time was running out to find survivors on Thursday as rescuers continued to work in the Kumamoto area on Japan 's southern main island of Kyushu, where the magnitude 7.1 earthquake hit on Tuesday.
The number of those missing was unclear.
Of the deaths given in the latest tally, 25 have been confirmed as related to the disaster, but there were nine more deaths under investigation as likely to be connected, the Kumamoto prefectural government said.
The quake left at least 86 people injured, five of them seriously, it said.
Survivors spoke about coming home and desperately pulling family members out of the wreckage.
Some had suffered injuries and were rushed to the hospital.
Thousands of people spent another night at evacuation centres set up throughout the area in gymnasiums and other big spaces.
Some homes were still without water or electricity, while others were simply afraid to go back.
Nearly 19,000 homes were still without electricity and more than 9000 people were staying in the roughly 400 shelters, where power sources were being added to provide air-conditioning.
Concerns were growing about illness, including from the sweltering heat. The Ministry of Environment sent out a heatstroke alert for the Kumamoto area, with temperatures expected to reach as high as 33C on Thursday.
In the town of Hikawa, one of the hardest-hit areas in Kumamoto, many residents are without water or electricity, or both, and some are staying inside their vehicles in parks or at the town hall parking lot.
At the front entrance of the town hall, officials delivered bottled water and packaged instant rice, while the Ground Self-Defence Force service members came with a trolley to provide fresh water.
Risks of heatstroke are a major concern among officials.
Yutaka Kobayashi, a doctor dispatched from central Japan's Aichi prefecture, said he was touring evacuation centres to assess the condition of evacuees, especially elderly people and those with injuries as they cope with a harsh environment.
"We have to make sure elderly people are not developing heatstrokes or dehydration," he said in Hikawa.
The most serious damage was at the Aeon shopping centre in the town of Kashima, which was bustling with thousands of people when the quake struck in the late afternoon.
The company said some 3000 customers were evacuated to a parking lot before the explosion happened in another part of the mall, where some people were still working.
The mall's second floor collapsed, trapping people.
As of early Thursday, six people were confirmed to have died at the mall site among the 11 people pulled out of the wreckage, according to Kumamoto authorities.
In the Yatsushiro area, where a chimney collapsed at a Nippon Paper Industries factory, 10 people were rescued, but eight others died, and one remained missing, according to the Kumamoto prefectural government disaster team.
Footage provided by the Japanese government and military showed rescue workers drilling through the collapsed parts of the building in an attempt to get to anyone who may still be trapped inside.
Prime Minister Sanae Takaichi told reporters the central government will take a lead role in coordinating the various rescue efforts.
Restoring electricity, gas and water to stricken areas, while providing a supply of fresh water is key, she said.
"The needs on the ground are constantly changing. To put to rest the people's feelings of uncertainty, we will do all that needs to be done," she said.
