Japanese emergency teams are airlifting supplies to communities affected by Talas, a powerful typhoon that left at least 37 dead and dozens more missing.

Aid-laden helicopters descended on towns in the hardest-hit areas as police, firefighters and soldiers mobilized to clear roads so that they could distribute food, medicine and other assistance to communities fending for themselves since Typhoon Talas made initial landfall on Saturday.

Japan's Kyodo news agency reported that dozens of hamlets in central Japan were still cut off, primarily because of flooding, landslides or other damage to access roads. Officials said they did not have an overall number for the stranded.

More than 3,000 remained in evacuation centres, however.

As Talas approached Japan, nearly a half million people were advised to evacuate. It then dumped record amounts of rain on central and western Japan and lashed wide swaths of the country with destructive winds before being downgraded to a tropical storm.

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Japanese Ground Self-Defence Force helicopters are being used to ferry people out of villages left isolated after Talas, a typhoon that was later downgraded to a tropical depression. ((Reuters))

Japan's Fire and Disaster Management Agency said 37 deaths had been confirmed and 54 people were still missing Tuesday. Japanese media reported at least 39 people had died.

The path of the typhoon did not take it over the tsunami-devastated northeast coast, where nearly 21,000 people were killed or are missing after the March 11 disaster.

But as the eye of the slow-moving storm hovered offshore in the Sea of Japan on Tuesday, heavy rains began to fall anew on the northern island of Hokkaido, prompting evacuation advisories for hundreds of households as rivers began to swell.

Talas, a word from the Philippines that means "sharpness," is Japan's worst storm since 2004, when Typhoon Tokage left 98 dead or unaccounted for.