MATAMOROS, Tamaulipas — The leaders of two of the most powerful drug cartels in Mexico gathered to strengthen alliances, draw new routes and territories for the smuggling of drugs, and discuss battle plans against shared rivals.

The meeting was exclusively confirmed to Breitbart Texas by a witness to the event. Last week, while the world tuned in to the U.S. elections, the leaders of the Gulf Cartel in Matamoros met with their counterparts of the Los Zetas Vieja Escuela (Old School Z), in an effort to solidify an alliance dubbed the “Carteles Unidos” (United Cartels). Mexican federal intelligence officials separetly confirmed the accuracy of the meeting witness’ claim to Breitbart Texas.

The meeting occured in the downtown area of Matamoros beginning at 11 a.m. local time and lasted for more than 6 hours. Those in attendance left after 5 p.m. in a discreet fashion. The event was organized by Sergio “Sr. Cortez” Ortegon, who is the current leader of the Gulf Cartel in Matamoros. Those in attendance included leaders of the Zetas Vieja Escuela group from Oaxaca, Tabasco, Nuevo Leon, San Luis Potosi, Coahuila, Veracruz, and Quintana Roo.

Breitbart Texas has reported in the past that the Vieja Escuela Zetas faction of the Los Zetas has been at war with the faction called Cartel Del Noreste (CDN). The fighting between the two has sparked widespread violence in Tamaulipas and spread to other states, including Nuevo León and Coahuila.