A head-on collision between two trains on the line that services Peru's Machu Picchu killed one person and injured at least 40 others, 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.

Officials said they were working to identify the injured train passengers, many of them foreign visitors and most of them seriously hurt.

Four tourists were from the mainland, the Chinese Embassy in Peru told Xinhua, and had been taken to hospitals.

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

Police wearing hardhats and neon-colored jackets carried injured passengers on stretchers from the trains to receive treatment.

A Unesco World Heritage Site since 1983, the ancient fortified complex of Machu Picchu receives some 4,500 visitors on average each day, many of them foreigners, according to the tourism ministry.

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

Rail agency Ferrocarril Transandino said a train operated by PeruRail collided with another belonging to Inca Rail around lunchtime on the single track that links the town of Ollantaytambo with Machu Picchu.

The cause of the accident was not yet known.

The Inca empire's ancient capital Machu Picchu was built in the 15th century at an altitude of 2,500 metres on orders from the Inca ruler Pachacutec.

It is considered a marvel of architecture and engineering. (AFP)