Nearly a dozen people, including several foreigners, were injured when two trains collided Tuesday near Peru’s most popular tourist destination, the Incan ruins of Machu Picchu.

The two competing train companies crashed along the main route transporting tourists to the Unesco world heritage site in Ollantaytambo village, the Guardian reports.

Peru’s civil defense institute said at least 10 people were injured in the passenger train collision, five seriously.

A police officer in Ollantaytambo, Edson Quispe, provided a higher count, telling Reuters that 23 passengers sustained injuries.

It remains unclear what caused the collision.

Eyewitnesses told the Guardian that a train operated by PeruRail collided into the backend of a train operated by IncaRail.

Before the crash, a group of Peruvian tourists reportedly stage a protest over being unable to board the train at an entry point reserved for locals.

“We stopped for an hour, then the protest was cleared, the train continued its route, and five minutes later we felt a strong impact on the back. It was a PeruRail train that hit us,” Valeria Lozana told the state news agency Andina, according to the Guardian‘s translation.

Pictures posted to social media showed the shattered glass and blown out windows of one of the train carriages. Other images captured the trains smacked together on the tracks.

https://twitter.com/portalturismope/status/1024381660211625984

IncaRail said only one of its passengers, a Chilean woman, was injured in the collision, while PeruRail said some passengers were taken away in ambulances.

Get The Brief. Sign up to receive the top stories you need to know right now. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Write to Laignee Barron at Laignee.Barron@time.com.