KUMAMOTO, Japan - The death toll from a magnitude 7.1 earthquake that jolted the southwestern Japanese prefecture of Kumamoto exceeded 30 on Thursday, as thousands of evacuees endured disruptions to essential services in sweltering summer heat while rescue workers raced against time as the critical 72-hour window since the disaster neared its end.

The tally includes eight people at a Nippon Paper Industries Co. plant in Yatsushiro that was severely damaged by Tuesday's quake and seven workers at an Aeon shopping mall in Kashima, where an explosion occurred after the quake. The prefectural government put the total death toll from the quake at 34.

Police, firefighters and Self-Defense Forces personnel combed through debris for signs of life as the 72-hour rescue window expires Friday afternoon.

Excluding the deaths at the Nippon Paper plant and Aeon shopping mall, the prefectural government said 10 people were confirmed dead, and nine other deaths may be linked to the quake, which registered the maximum 7 on the Japanese seismic intensity scale in parts of Kumamoto.

Vietnam News Agency has reported that one Vietnamese trainee died after being crushed by a crane at a factory in Kosa.

More than 9,000 people stayed in shelters in Kumamoto, which was ravaged by similarly powerful earthquakes in 2016, as thousands of households remained without electricity and water.

People gathered around water trucks to receive water while others formed long lines to fill their cars at gas stations.

A woman in her 70s from Uki, one of the hardest-hit areas, is staying at an evacuation shelter but spends the night in her car with her pet dog.

She lined up for two and a half hours Thursday morning at a gas station to fill up her car in preparation for an extended evacuation. "I am tired, and my dog is getting weak because of the heat. I wonder when this will be over," she said.

High temperatures are forecast in quake-hit areas, raising concerns about heat-related illnesses, especially in places without adequate air conditioning, as evacuation fatigue continues to mount.

Prime Minister Sanae Takaichi, who has vowed to ensure the timely delivery of supplies to those affected, could visit Kumamoto as early as Monday, government sources said.

There has been a discrepancy in casualty figures released by the central government and Kumamoto, as the central government relies on data from the police and fire departments, while the prefecture compiles figures reported by municipalities, Chief Cabinet Secretary Minoru Kihara said at a press conference in Tokyo.

At the Hikawa municipal office, Masako Uraguchi, a 77-year-old from neighboring Yatsushiro, queued to receive water from an SDF water truck. Each person was allowed up to 5 liters.

"It's so inconvenient because we can't flush the toilet. We cannot survive without water in the heat," she said.

As of 2 p.m. Thursday, about 80,000 households in the prefecture were without running water, according to the local government.

About 14,000 households in the prefecture were without electricity as of Thursday evening, according to Kyushu Electric Power Transmission and Distribution Co. The company aims to restore power by Friday evening.

The disaster also disrupted business activity in Kyushu, one of Japan's four main islands.

Toyota Motor Kyushu Inc. will suspend operations at three plants through Friday, while Mitsubishi Motors Corp. has decided to halt production of some vehicles at its plant in Kurashiki, Okayama Prefecture, from Thursday night after the earthquake disrupted its supply chain.

The quake has also hit local chipmakers, as production at a plant operated by Taiwan Semiconductor Manufacturing Co., the world's leading chipmaker, has yet to return to normal.

The company said it still needs more time to adjust its equipment.

JR Kyushu said services on sections of the Kyushu Shinkansen Line between Fukuoka and Kagoshima prefectures were suspended.

When an earthquake measuring 7 on the seismic scale strikes, people cannot remain standing or move without crawling and may be thrown through the air, according to the Japan Meteorological Agency.

Related coverage: