TLAXCALA (Reuters) - At least 11 people were killed and 36 others injured on Friday when a truck containing fireworks exploded in a freak accident in the central Mexican state of Tlaxcala, casting a pall over a Catholic procession in honor of a local patron saint.

The explosion was ignited when a stray firework fell into a truck carrying more fireworks, said Jose Mateo Morales, director of emergency services for Tlaxcala state.

The fireworks were set to be used in a ceremony honoring Jesus Tepactepec, patron saint of a village named after him in the municipality of Nativitas. The blast happened on the highway just outside the village.

(Reporting by Imelda Medina, Lizbeth Diaz and Adriana Barrera; Writing by David Alire Garcia; Editing by David Brunnstrom)