A Swiss hamlet was being evacuated Friday after authorities determined the unstable mountain towering above could come raining down in a few days.

Access to the small village of Brienz in far-eastern Switzerland will be off limits from 6pm (1600 GMT), local authorities said.

Towering over Brienz is an unstable mountain with around two million cubic metres of rock that is slipping and threatening to break loose.

Brienz's 84 residents have been aware for some time that an evacuation might be necessary. Earlier this week they received an emergency notice saying they needed to be out by Friday.

The residents are being temporarily accommodated at a safe distance.

"The analysis by the early warning service shows that the rock is expected to break off in the next four to 14 days," the Albula municipality said.

The evacuation would be complete by 6pm, it said, adding that "after that, no residents nor farm animals will be permitted in the village".

"If the rock breaks off, there is a danger to life in the closed-off area," it said, adding that emergency services would be permitted in under special security precautions.

Switzerland's Federal Office for Civil Aviation has also issued a no-fly zone over the village, located at an altitude of 3,050 metres.