A surge in demand for rest cabins on Mount Fuji has led Japanese officials to call for crowd control measures including potential entry restrictions during this summer's climbing season.

Local authorities and tourism associations near the famous volcano warned that an "unprecedented" number of people were expected to tackle its steep symmetrical slopes this year.

They raised safety concerns in a petition submitted on Monday to the governor of Yamanashi region, where the sacred mountain's most popular hiking trail is located.

Crowds could be larger than usual due to the relaxation of COVID restrictions, including the return of foreign tourists, and the 10th anniversary of the peak's designation as a UNESCO World Heritage Site.

"Judging from the current status of reservations for nearby cabins, we estimate there will be an unprecedented number of hikers on Mount Fuji this summer," the petition said.

Japan's highest mountain is capped with snow for most of the year and is open to climbers from July to September—drawing hundreds of thousands who often trek through the night to see the sunrise.

Those unable to book a mountain cabin may climb straight to the summit without stopping to rest, which "could increase the risk of altitude sickness and hypothermia", warned the group of officials.

If numbers exceed a certain limit, entry restrictions should be considered "even for just a short amount of time", they said, without specifying what the maximum should be.

Busy trails also raise the risk of rockfalls, an official from the city of Fujiyoshida, one of the six municipalities behind the petition, told AFP on Tuesday.

"We're all worried that this year's Mount Fuji hiking season will create a terrible situation," said the official, who declined to be named.

She said she was especially worried that tourists from overseas, who are not necessarily aware of the treacherous nature of Mount Fuji, may ascend the peak unprepared.

"We really want them to be careful. There are deaths every year," she said.

"It's not that easy, hiking Mount Fuji."

The 3,776-meter (12,388-foot) active volcano is about two hours from central Tokyo by train.

But it can be seen for miles around, and has been immortalized in countless Japanese artworks, including Hokusai's world-famous "Great Wave".

© 2023 AFP