Heavy snow piling up in northern Japan in the past two weeks has blocked roads and is being blamed for dozens of deaths nationwide.

As of Wednesday, 15 prefectures have been affected, with snow reaching up to two metres in worst-hit areas. The unusually heavy snowfall is largely due to a cold air mass from the Arctic that has lingered over the Japanese archipelago.

More than 1,700 homes were without electricity, and most train lines weren’t running, including the bullet trains, according to Aomori prefecture.

“We anticipate some roads might get blocked off, and so we are consulting with services that can help with ambulances and fire trucks to get through to their destinations,” Aomori governor Soichiro Miyashita said on Wednesday.

Emergency vehicles that weren’t able to get to their destinations had parked nearby, and medical staff gone on foot with stretchers to rescue people in need, he said.

Miyashita said he was asking the city of Aomori to try to clear the main roads of snow, implying that the city is falling behind others. Schools in Aomori were shut, affecting thousands of schoolchildren, he added.

Most of the 35 deaths and hundreds of injuries reported across Japan were caused by falls among people trying to clear their homes of snow.

Twelve of the snow-related fatalities were reported in Niigata prefecture, a rice-growing region in northern Japan, including a man who was found collapsed on the roof of his home in Uonuma city. In Nagaoka city, a 70-year-old is believed to have died after falling from his roof, according to the Niigata government.

Japan’s chief government spokesman Minoru Kihara warned that although the weather was getting warmer, more danger could lie ahead because snow would start melting, resulting in landslides and slippery surfaces.

Injuries nationwide numbered 393, including 126 serious injuries, 42 of them in Niigata. Fourteen homes were damaged, three in Niigata and eight in Aomori prefecture.

More heavy snow is forecast for the coming weekend in northern Japan. (AP)