The death toll from Japan’s devastating floods has climbed above 200 as experts warned further casualties were still possible.

Yoshihide Suga, the government’s chief cabinet secretary, said 204 people were now known to have died with 28 still missing, following the country’s worst weather disaster in 36 years last week.

But he added: "People still need to be aware of the possibility of further landslides."

Scorching summer temperatures, water shortages and litter-strewn streets have also prompted fears of disease outbreaks in the worst affected areas of Okayama, Hiroshima and Yamaguchi prefectures.

As more than 70,000 workers continued to clear through mud and debris, thousands of evacuees remained camped outside or in temporary shelters. Almost 240,000 homes are still without running water.

The government has sent tankers to the disaster areas, but fears have grown that survivors were not receiving enough fluids due to tight supplies.

"We need the water supply back," Hiroshi Oka, 40, a resident in the Mabi district of Okayama told Reuters. "What we are getting is a thin stream of water, and we can't flush toilets or wash our hands.”

Houses submerged by muddy water following heavy rains in Kurashiki in Okayama prefecture (AP)

Shizuo Yoshimoto, a doctor making the rounds at evacuation centres, said: "There are quite a few cases where patients are unable to get a hold of drugs. So one issue is how to maintain treatment for those with chronic illness. Another is acute illness, as heatstroke is on the rise."

He added that local hospitals were reporting delayed surgeries and that dialysis patients were having to be transferred in order to undergo treatment.

The record downpours caused widespread landslides, flooding and burst riverbanks across much of western and parts of central Japan last week, forcing more than two million residents across 29 prefectures to flee their homes.

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

Severe weather has increasingly battered the country in recent years, including similar floods last year that killed dozens of people.

Shinzo Abe, the Japanese prime minister, cancelled a scheduled overseas trip to deal with the rescue effort and visited several effected regions on Friday.

He said: “Preserving the lives and peaceful existence of our citizens is the government's biggest duty. We recognise that there's a need to look into steps we can take to reduce the damage from disasters like this even a little bit.”

Authorities have also struggled to maintain clean water supplies to those affected by the flooding, making the task of reducing the risk of disease spreading even harder.

A resident piles up household waste caused by flooding in Okayama Prefecture (Reuters)

"We need the water supply back," said Hiroshi Oka, 40, a resident helping to clean up the Mabi district in one of the hardest-hit areas, the city of Kurashiki, where more than 200,000 households have gone without water for a week.

"What we are getting is a thin stream of water, and we can't flush toilets or wash our hands," he added, standing over a 20-litre plastic tank that was only partly filled after almost four hours of waiting.