On 26 July 2011 in Ciudad Juárez, Chihuahua, a prison brawl left 17 inmates dead and 4 injured after "one group of inmates attacked rivals from another drug gang." Some of the corpses were shot with assault rifles, and authorities investigates whether the weapons used in the attack were "stolen from prison guards, homemade or smuggled" inside the prison. Surveillance videos show how two gangs of the Sinaloa Cartel and the Juárez Cartel stormed the prison with assault rifles. In a prison in Cadereyta Jiménez, Nuevo León, 7 inmates were killed and 12 were injured on 14 October 2011.
