A head-on collision between two tourist trains near Peru’s famous Machu Picchu killed a train driver and injured at least 40 people on Tuesday, authorities said. The crash occurred on the railway route to the ancient Inca citadel, one of the country’s top tourist destinations, with the trains operated by Inca Rail S.A. and PeruRail S.A. Police have launched an investigation, and a regional health official said about 20 of the injured were in serious condition, while others sustained minor injuries. Several foreign tourists were among those hurt.

Images show the locomotives heavily damaged and facing each other on the tracks, with shattered glass scattered as emergency responders treated passengers. Authorities are reviewing the circumstances leading up to the crash to determine responsibility and prevent future incidents.