TOKYO — Rescuers used heavy machinery, shovels and dogs in the seaside city of Atami on Monday as they searched desperately for survivors from a landslide that has left at least four people dead and 24 missing.

Two people were found unharmed Monday, public broadcaster NHK reported, two days after a “tsunami” of mud swept away scores of buildings, following torrential downpours. At one point, officials had said 147 people were missing, but that number was gradually whittled down as many were found to have evacuated or were simply not at home. The tally is complicated because many houses in Atami are vacation homes or rentals.

Atami, a city of 36,000 people, lies 60 miles southwest of Tokyo. It is set on a steep slope leading down to a bay and is famous for a hot-springs resort.

“It was a matter of a few minutes,” a woman who posted a video of the mudslide told the Mainichi newspaper, explaining that the entire family had escaped out a window. “My only thought at seeing the mudslide was fear, and I felt like I was just going to die”

Eiji Suzuki said he had rushed out of his house after hearing a sudden noise and saw the mudslide approaching. He tried to go back home to help his 82-year-old mother, but police told him to evacuate the area and said they would rescue her.

They did, but she died at a hospital.

“The police urged me to evacuate, but now I regret leaving my mother behind,” he told Mainichi. “She was a truly kind person. Thinking of all of our memories together, I am devastated. ”

Some areas had received more rain in 24 hours than they normally receive in the whole of July, but nature may not have been entirely to blame.

Shizuoka Gov. Heita Kawakatsu said the prefecture was looking into whether development projects played a role by leaving a large mound of dirt that appears to have collapsed into the river, while also deforesting the area and reducing the capacity of mountain soil to retain water, according to Japanese media reports.

Chief Cabinet Secretary Katsunobu Kato called for vigilance, with the ground so saturated and weakened that even light rain could prove dangerous, but Prime Minister Yoshihide Suga vowed an all-out effort to rescue any survivors. “Police, Self-Defense Forces, firefighters, the Japan coast guard and others are dedicating all their strength to rescue every person who has been left in the debris who needs help as soon as possible,” he told reporters.

A 75-year-old man had a lucky escape when the house across from his was swept away. The couple living there are missing.

“This is hell,” the man told the Reuters news agency from an emergency shelter.

Julia Mio Inuma contributed to this report.