Regional police commander Col Julio Prado says the cause of the accident is under investigation.
He says it happened about 4:20 am yesterday in a farming community in the Acoria district of the Huancavelica region about 246 kilometres southeast of Lima.
Deadly bus accidents are frequent in Peru, where enforcement of road safety rules is weak. Government figures say 5,435 people died and 13,520 were injured in bus crashes between September 2008 and December 2012.
