An early-morning accident on Thursday involving a bus and a gas truck carrying 40,000 liters of fuel in central Nuevo León left 12 dead and five injured amid a large conflagration that shut down traffic.

The crash occurred before dawn on the Colombia Highway in the municipality of Salinas Victoria. While authorities did not confirm the cause of the accident, the newsmagazine Proceso reported that the truck and bus crashed after they both went around a pronounced curve in the highway.

The bus, which the newspaper El Heraldo de México said had been heading to the city of Monterrey, was left on its side with its front section nearly detached, according to Proceso.

The gas truck, which authorities said exploded upon impact, was engulfed in flames, and diesel fuel leaked for several meters around it.

The driver of the truck was among the dead, authorities said.

The highway was shut down while state and local emergency personnel doused the flames and rescued the injured, who were taken to various hospitals in the area, according to Miguel Perales, head of Nuevo León’s Civil Protection agency.

The fire was out by around 6:15 a.m., authorities said.

Source: El Universal (sp), ADN40 (sp), Proceso (sp), El Heraldo de México (sp)