At least 155 people have been killed after torrential rain unleashed floods and landslides across western Japan in the country’s worst weather disaster for 36 years.

Rescuers were searching for around 67 people who remain missing, many of them in the hardest-hit Hiroshima area.

The country’s prime minister, Shinzo Abe, cancelled an overseas trip to oversee the emergency response to the disaster, which at one point forced several million people from their homes.

Mr Abe, who had been due to visit Belgium, France, Saudi Arabia and Egypt, faced criticism after he was pictured dining with the defence minister and other lawmakers last week, as the rains began to worsen.

Survivors face health risks from high temperatures and a lack of water.

Power has been restored to all but 3,500 homes, but more than 200,000 people remain without water under the scorching sun, with temperatures hitting 33C in some areas.

Heavy rain leads to flooding and landslides in Japan Show all 15 1 /15 Heavy rain leads to flooding and landslides in Japan Heavy rain leads to flooding and landslides in Japan People await resuce in Kurashiki, Okayama prefecture AP Heavy rain leads to flooding and landslides in Japan A car stands on its nose in Okayama prefecture as flooding hits Japan Getty Heavy rain leads to flooding and landslides in Japan A rescue helicopter is on the scene of a landslide in Iwakuni, Yamaguchi prefecture AP Heavy rain leads to flooding and landslides in Japan An emergency crew attends to a train that has been derailed by a tree on the tracks. Heavy rain has caused landslides in Saga prefecture AFP/Getty Heavy rain leads to flooding and landslides in Japan Kurashiki, Okayama prefecture AFP/Getty Heavy rain leads to flooding and landslides in Japan A car is trapped in mud flows in Saka, Hiroshima prefecture AFP/Getty Heavy rain leads to flooding and landslides in Japan Kurashiki, Okayama prefecture AFP/Getty Heavy rain leads to flooding and landslides in Japan Rescue teams transport people from the Mabi Memorial Hospital in Kurashiki, Okayama prefecture AFP/Getty Heavy rain leads to flooding and landslides in Japan Kurashiki, Okayama prefecture AFP/Getty Heavy rain leads to flooding and landslides in Japan Soldiers search for victims in Kurashiki, Okayama prefecture AFP/Getty Heavy rain leads to flooding and landslides in Japan A road is damaged in Kurashiki, Okayama prefecture AP Heavy rain leads to flooding and landslides in Japan Rescue teams attend to inpatients, staff and residents at the Mabi Memorial Hospital in Kurashiki, Okayama prefecture EPA Heavy rain leads to flooding and landslides in Japan Kurashiki, Okayama prefecture EPA Heavy rain leads to flooding and landslides in Japan Police clear debris in Kumano, Hiroshima prefecture AFP/Getty Heavy rain leads to flooding and landslides in Japan Residents take shelter in an evacuation centre in Kurashiki, Okayama prefecture AFP/Getty

“There have been requests for setting up air-conditioners due to rising temperatures above 30 degrees today, and at the same time we need to restore lifelines,” Japan’s finance minister, Taro Aso, told reporters after a cabinet meeting.

The transport of relief goods has been delayed by damaged roads and transport systems.

The government has set aside 70bn yen (£475m) in infrastructure funds with 350bn yen (£2.38bn) in reserve, Mr Aso said.

He went on to say an extra budget would be considered if needed: ”When necessary amounts firm up ... we would consider an extra budget later on if these funds prove insufficient.”

Although Japan issues weather warnings early, its dense population means almost every bit of usable land including some flood plains is built on in the mostly mountainous country, leaving it prone to disasters.

A new evacuation order went out on Tuesday in a part of Hiroshima after a river blocked by debris overflowed its banks, affecting 23,000 people.

Another storm, Typhoon Maria, was bearing down on outlying islands in the Okinawa chain but it had weakened from a super-typhoon and was not expected to have any impact on Japan’s four main islands.