Thousands of people remained stranded in western Japan Tuesday after the death toll from a fierce typhoon rose to 41, heaping more misery on a nation recovering from the March earthquake and tsunami.

Torrential rain brought by powerful Typhoon Talas, which made landfall Saturday and was the deadliest in seven years, caused rivers to swell and triggered floods and landslides that swept away buildings, homes and roads.

More than 50 people were still missing, local authorities contacted by AFP said.

As police, firefighters and self-defense force troops continued their painstaking search for the missing, local authorities were planning to air-drop more food and water to those isolated by the disaster.

In severely affected Wakayama, about 4,500 people remained stranded in communities that could not be reached due to collapsed roads, according to a local official.

In Totsukawa village in Nara, more than 400 people were stranded in evacuation shelters as access routes have mostly been cut off and phone lines were down in most parts of the village, a local official said.

"After carrying 1,000 litres of drinking water by helicopter yesterday, we are planning also to transport rice, instant noodles and drinks later today," the official said.

"The rescue work is expected to take time," the official said.

Talas, which moved away from Japan on Sunday, has since been downgraded to a tropical storm but the remnants of its weather system, together with the impact of new Typhoon Noru, continued to inflict heavy rains on northern Japan.

The storm came after new Prime Minister Yoshihiko Noda was sworn in on Friday, replacing Naoto Kan, who was heavily criticised for the government's response in the aftermath of the March 11 disasters and nuclear crisis.