A Public Safety Department official for the state of Zacatecas confirmed the figures and said some of those hurt had grave injuries. The official was not authorized to be quoted by name and spoke on condition of anonymity.

Authorities were investigating the company that owns the truck and were searching for the driver, who apparently fled the scene of the crash.

The truck, which officials said was loaded with building materials, apparently lost its brakes and ran into the crowd Wednesday on a main street in the town of Mazapil.

Video images showed bodies lying on the ground and two smashed pickup trucks. Masked and gloved emergency workers milled about the scene, which was cordoned off with yellow police tape.

The town was celebrating the festival of its patron, Jesus Nazareno, with a procession to the church of San Gregorio Magno.

Such processions are common in Mexico to celebrate a saint's day or special religious occasion. Participants often walk on roads to local shrines.