French authorities have introduced new rules that require people who want to scale Mont Blanc by the standard route to book a room in one of its three shelters if their bid includes the usual overnight stay.

The rule, which goes into effect on Saturday and applies until the end of the climbing season in September, has been introduced amid concerns about overcrowding and rockslides on the 4,810-meter (15,780-foot) mountain. Fifteen climbers died on Mont Blanc last year, and a 25-year-old man from Slovakia fell to his death on Friday at the start of the route, commonly known as the "Route Royale."

Nearly 25,000 climbers undertake the ascent each year.

Prison and fine

Under the new rules, climbers caught camping illegally on the route could face a two-year prison sentence and a €300,000 ($335,000) fine, said regional administrator Pierre Lambert.

Lambert said that he had decided to impose the rule about booking a room as climbing the mountain by the normal route "meant at least one overnight stay for the great majority of mountaineers."

He said the overcrowding at the shelters had led to problems with sanitation and security, with one shelter caretaker even being physically threatened.

The new rules come as concerns grow about overcrowding on the world's highest mountain, Mount Everest, where eight people have died in a week. A traffic jam of climbers on Everest has been blamed for two of four new fatalities reported on Friday in the peak's "death zone."

Read more: Cleaning up Mount Everest – the world's highest rubbish dump 

Every evening at 1830 UTC, DW's editors send out a selection of the day's hard news and quality feature journalism. You can sign up to receive it directly here.