Peru has evacuated around 1,600 tourists from a train station that serves the Inca citadel of Machu Picchu after a local protest escalated into clashes with police.

A UNESCO World Heritage Site since 1983, the ancient fortified complex receives around 4,500 visitors a day, many of them foreigners, according to the tourism ministry.

Visitors travel some 110 kilometers (68 miles) by train from the city of Cusco -- the Inca empire's ancient capital -- to the Aguas Calientes train station, then take a bus to the entrance of Machu Picchu.

Residents placed logs and rocks on the tracks Monday to demand that their interests be represented in the bidding process for the new bus operator, after the previous firm's 30-year concession expired.

Authorities on Tuesday evening evacuated 156 visitors,

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