A group of bus passengers overpowered two would-be robbers, beating one to death and leaving the other badly injured, Mexican police said Thursday.

The incident took place before dawn on the highway linking the northern cities of Monterrey and Durango.

Before the bus reached Saltillo, according to the passengers, one of the assailants rose from his seat and walked toward the back of the vehicle, brandishing a large wrench, while his partner approached the driver with knife in hand and demanded the riders’ belongings.