A head-on collision between two trains on the route to Machu Picchu in Peru has left one person dead and at least 40 injured, authorities said.

The deceased was the conductor of one of the two trains, according to the prosecutor’s office in Cusco, the city closest to the famous Inca citadel.

The American Embassy in Peru said that among the injured were American citizens. It was not indicated how many Americans were injured or the extent of their injuries.

Videos sent by passengers to the RPP television channel show the injured victims lying next to the tracks, while two damaged locomotives stand idle nearby.

A dozen ambulances and medical personnel were rushed to the site in a remote area of ​​the Andes without direct road access.

Inscribed on the UNESCO World Heritage List since 1983, the ancient fortified complex receives about 4,500 visitors on average every day, many of them are foreigners, according to the Ministry of Tourism.

Most tourists take the train and bus to the historic site high in the Andes mountains.

Rail agency Ferrocarril Transandino said a train operated by PeruRail collided with another train belonging to Inca Rail around lunchtime on a line connecting the city of Ollantaytambo to Machu Picchu.

The cause of the accident was not yet known.

Machu Picchu was built in the 15th century at an altitude of about 2,200 feet by order of the Inca ruler Pachacutec.

It is considered a marvel of architecture and engineering.