At least 19 people have died in snow-related incidents after the record-breaking storm, the top-selling Yomiuri Shimbun reported, with the blast now battering the northern island of Hokkaido.
More than 6,900 people were trapped in small communities cut off by snow-blocked roads and railway lines, the Yomiuri said, while gasoline deliveries to some petrol stations were delayed due to impassible roads.
In Yamanashi prefecture west of Tokyo, stores were facing a serious fresh food shortage, the Yomiuri and public broadcaster NHK reported, with Prime Minister Shinzo Abe promising to send a government team to help the struggling area.
The storm is now moving toward northernmost Hokkaido, Japan's meteorological agency said, warning of heavy snow, blizzards and avalanches as well as high waves along the northeastern coast, which was battered by a quake-sparked tsunami almost three years ago.
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Despite around-the-clock clearing efforts, hundreds of cars today remained stuck on some mountain roads, leaving drivers stranded, local officials told AFP.
National Route 18 that runs through Gunma and Nagano prefectures north of Tokyo is still partly closed, with cars stuck along several kilometres due to the heavy snow.
"Efforts to remove snow from the roads are continuing with Self-Defense Forces servicemen working from 7:00 am (local time) this morning," said an official at the Karuizawa ski resort in Nagano prefecture.
The transportation ministry and municipal governments are delivering emergency aid to drivers of stuck cars, officials said.
Snow began falling Friday morning in the capital Tokyo and had piled up to 26 centimetres by early Saturday, a week after the heaviest snowfall in decades left 11 people dead and more than 1,200 injured across the nation.
Most snow in the capital had melted, but forecasters predict more snow again in the region around Tokyo later this week.