Two children and 17 adults were killed after a bus in southern Peru ran off a remote road in the Andes and fell 80 metres into a ravine, police said.
Eighteen more people were injured in the accident.
Regional police commander Julio Prado said the cause of the accident was under investigation.
He said it happened in the early hours of Sunday in a farming community in the Acoria district of the Huancavelica region about 246km southeast of Lima.
The bus, which belonged to the company Antezana, was travelling through a curvy ravine area in the Andes.
One injured person told regional police that the driver was travelling at excessive speed on a narrow and windy road, local radio reported.
Deadly bus accidents are frequent in Peru, where enforcement of road safety rules is weak.
According to a report by the government's National Institute of Statistics and Information, 781 people died in Peruvian traffic accidents in the first quarter of 2013.
The Peruvian Attorney General's Office says the main causes of such accidents are bus drivers' recklessness, excessive speed, alcohol drinking and sleepiness.