The quake, which struck Saturday evening in the province of Paruro in the Cusco region, had a magnitude 4.8, the seismological institute said.
The epicentre was 40 kilometres south-east of Cusco.
The earthquake caused 60 houses to collapse and damaged several others.
The Andina news agency said emergency responders had been sent to the region. It said the magnitude of the earthquake was 5.1. There was no explanation for the discrepancy.