Officials in Japan have dramatically raised their estimate of the number of people still missing after a mudslide ripped through a seaside town at the weekend.

Reports said three people had died in the disaster, which occurred after days of torrential rain in Atami, a famous hot spring resort about 60 miles (90 km) south-west of Tokyo.

Officials had initially said about 20 people remained unaccounted for, but the number rose to 113 after they checked residential registers rather than relying on reports of missing people.

A man walks by a collapsed road caused by heavy rain in Kuma, Kumamoto prefecture. Flooding and heavy rains have killed 58 people.

“We’re in touch with various groups and pushing forward with the search,” local spokesman Hiroki Onuma told Reuters. So far, 23 people have been rescued, the municipal government said.

Onuma said the rain had stopped in Atami but added that more was forecast. “The situation is unpredictable,” he said.

Several landslides crashed through part of the town on Saturday morning, sending torrents of mud and rock through streets and destroying about 130 buildings.

The prime minister, Yoshihide Suga, said police, firefighters and soldiers from the self-defence forces were trying to locate survivors. “We want to rescue as many victims who have buried in the rubble as we can, and as soon as possible,” he said.

The governor of Shizuoka prefecture, Heita Kawakatsu, said authorities would investigate if building projects in the area had reduced the mountain’s ability to retain water and triggered the mudslide.

“The prefecture will examine the causal relationship between the two factors,” the Kyodo news agency quoted him as saying.

Heavy rainfall exceeded the usual monthly total for July in just 24 hours, loosening huge quantities of soil that cascaded down steep slopes leading to the Pacific Ocean.

With much of Japan affected by the annual rainy season, the meteorological agency said heavy rain was also expected on the opposite side of the country and warned people to be vigilant against further mudslides, flooding and swollen rivers.

“My mother is still missing,” a resident of Atami told the public broadcaster NHK. “I never imagined something like this could happen.”

Naoto Date, who returned to his home town to check the damage, said the mud had coursed down a steep mountain slope and became a deluge when it reached a narrow river below.

“I just wanted to cry when I saw what had happened,” he said.