A train driver has died and at least 40 people have been injured in a head-on rail collision near Peru's most popular tourist attraction, Machu Picchu.

Two trains collided on the only tracks leading to the ancient Inca city on Tuesday, according to a statement from the local government, the Telegraph reports.

She said 20 ambulances had arrived at the scene and that the injured had been transferred to medical facilities in the nearby city of Cusco.

The US Embassy in Peru said American citizens were injured in the accident, but police have not yet confirmed the identities of anyone involved in the incident.

Local media outlet Peru21 reports that "hundreds" of tourists remain at the scene awaiting evacuation, which has been "hindered" by the difficult terrain surrounding the crash site.

At least 20 of the injured are in serious condition, a health official told Reuters news agency.

The collision occurred on the tracks connecting the Ollantaytambo station and Aguas Calientes, the closest town to Machu Picchu. The journey between the two stations usually takes about 90 minutes.

The two trains involved in the accident were operated by PeruRail and Inca Rail, respectively.

"We are very sorry for what happened," PeruRail said in a statement, adding that its staff had "immediately" provided first aid to the train driver, conductor and passengers involved in the incident.

The cause of the accident is not yet clear. The accident comes amid an ongoing dispute between transport providers to the UNESCO world heritage site, with local communities unhappy with what they say was an insufficiently transparent tendering process.

Trains and buses that take tourists to the ancient city have high ticket prices and can be very profitable due to limited access. /Telegraph/

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