A Mexican drug cartel has issued an ominous death threat against police officers in Nogales, AZ who seize their illicit product as reported by Sean Alfano for the Daily News:

Police Chief Jeffrey Kirkham said his officers received threats a couple weeks ago after off-duty police busted a pot smuggling ring. * * * Just which cartel made the threat remains unclear. Violent warnings toward American police are not new, but the Nogales incident marked the first time U.S. officials confirmed a threat.

The Sinaloa cartel controls the smuggling routes along the Arizona-Sonora border, and in early 2009 its boss Joaquin "El Chapo" Guzman "ordered his traffickers to use deadly force to protect loads passing through U.S. territory" as reported by Jonathan Clark for Nogales International.  Meanwhile, the Mexican drug trafficking organizations have established permanent base camps "in strategic locations in the hills of southern Arizona from which their scouts can monitor every move made by law enforcement officials" as reported by Adam Housley for FOX News. Earlier this month federal authorities closed U.S. park land in three Arizona counties along the Mexico border because it is no longer safe after the American territory was taken over by the violent drug cartels.