Ricardo de la Cruz, the assistant state interior secretary, said the accident occurred in the township of Joquicingo, southwest of Mexico City
19 people died and 32 more were injured after a bus apparently carrying pilgrims to a religious site in central Mexico crashed.
State officials said the bus apparently lost its brakes and slammed into a building in the State of Mexico Friday.
Six of the victims suffered injuries so severe they were flown to hospital in Toluca, the state capital.
Ricardo de la Cruz, the assistant state interior secretary, said the accident occurred in the township of Joquicingo, southwest of Mexico City.
The bus was heading from the western state of Michoacan to Chalma, a town that has been visited by Roman Catholic pilgrims for centuries.
There was no immediate information on the condition of the injured passengers. Many Mexicans go on religious pilgrimages as December 12, the day of the Virgin of Guadalupe, approaches.
Because they often walk or bike on narrow roads or travel in aging buses, accidents are not uncommon.
Mexico State borders Mexico City on three sides, and includes both remote rural villages and crowded suburbs of the capital.
Chalma was a site sacred in pre-Hispanic times before the 1521 conquest. After the Spanish came, believers say, a cross miraculously appeared in a cave that had been dedicated to an Aztec god, making Chalma a Christian pilgrimage site.