AP

MEXICO CITY (AP) — One of the military deserters who helped found the gang that grew into the brutal Zetas cartel was among six people killed during a gunbattle in a border town, a Tamaulipas state security official said Sunday.

The official said authorities confirmed that Galindo Mellado Cruz was one of five gunmen who died Friday in a shootout that also killed a Mexican soldier in Reynosa, which is across from McAllen, Texas. The official was not permitted to be quoted by name for security reasons.

The official said that Mellado Cruz was one of the 30 ex-special forces soldiers who created the Zetas gang to serve as enforcers for the Gulf Cartel before splitting off in a bloody breakup with its former ally. The official said Mellado Cruz no longer held a Zetas command position.

Tamaulipas became one of the arenas for fighting between the Gulf Cartel and the Zetas and was one of Mexico's most violent states. But the state had calmed somewhat by 2012, before violence re-ignited in recent weeks.