The vehicle, which carried 12 German tourists along with their Peruvian driver and another Peruvian, fell about 20 meters while traveling from the city of Arequipa to the town of Chivay around 3pm.
The surviving 10 German tourists and their two Peruvian crewmembers were taken to hospital in Arequipa, a police official in Chivay said.
Chivay, home to about 6,500 inhabitants, is located more than 3,600 kilometers above sea level in the mountains of the Colca Valley, a popular tourist destination in the South American country.
Hours earlier, another accident occurred in the same region that left seven dead and 18 injured, after a passenger bus fell into a 60-meter ravine.
A separate bus plunge on Friday, in the northern region of La Libertad, killed at least 11 people when it landed at the bottom of a 200-meter chasm, police said.
Peruvian authorities recommend driving with extreme caution in the winding and narrow Andean routes.
On January 2nd, 52 people died, while 45 were killed on February 21st — in both cases after passenger buses fell into ravines of nearly 100 meters.
Almost 2,700 people died in traffic accidents in Peru in 2016, according to official figures. The data for 2017 have not yet been published.