The driver of the bus likely lost control of the vehicle, causing it to drop nearly 800 meters (2625 ft) off a precipice in the southwestern municipality of Yocalla, a police officer speaking from the local hospital said, Reuters reported.
Of those injured in the crash, 10 adults and four children had been hospitalized, with several in intensive care, an official from the hospital said in a video.
The mountainous route is full of twists and turns, the police officer said, adding that the bus' speed could have been a factor in the crash.