GENEVA — Authorities in eastern Switzerland on Saturday ordered residents of a small village to prepare to evacuate as an Alpine landslide threatened to break loose and fall on their homes.

This was the second time that residents of Brienz received evacuation orders after a similar threat last summer.

Local authorities said in a statement to villagers that “well above Brienz, the upper part of the highest part of the rubble pile has accelerated considerably. It cannot be ruled out that up to 1.2 million cubic meters of rock debris will move down the valley in a debris flow.”

Measurements taken by the municipality’s warning service showed that the top of the pile of rubble was sometimes moving at a speed of more than 30 centimeters (11.8 inches) per day since the second half of September, a reported public broadcaster SRF.

They said if the landslide starts to accelerate, it could soon reach the village.

The centuries-old village straddles the German- and Romansh-speaking parts of the eastern Graubünden region, southwest of Davos, at an altitude of about 1,150 meters (about 3,800 feet). Today, it has less than 100 inhabitants.

The mountain and the rocks that make it up have been moving since the last ice age, according to local authorities.

Over the past century, the village itself has moved a few centimeters each year, but the movement has accelerated over the past 20 years. The landslide moves about a meter (about 3 feet) per year.