Ancash province health director Carlos Segovia says that among the dead is a 1-year-old baby.
The accident took place on a mountain highway in Mayorarca, Ancash before noon yesterday.
Segovia said the overcrowded bus flipped over and plunged into an abyss about 216 kilometers (134 miles) northeast of Peru's capital, Lima.
In October, 51 Quechua farmers died in southeastern Peru in the country's worst highway accident in three decades.
The high-altitude roads of the Peruvian Andes are notorious for bus plunges, with poor farmers comprising many of the victims. Last year, more than 4,000 people were killed in such accidents.
