People wait in line to cross the border between Mexico and the US in Tijuana, Mexico, May 6, 2006. REUTERS/Carlos Barria

The Jalisco Nueva Generación cartel — one of Mexico's strongest and fastest-growing criminal organizations — is moving into Baja California, just across the border from the US, according to an official from the Mexican attorney general's office.

It seems increasingly likely that the CJNG, as the cartel is known, is challenging the powerful Sinaloa cartel for control of drug-smuggling territory there.

The announcement from Gualberto Ramírez Gutiérrez, the head of the kidnapping unit within the Mexican attorney general's office, came after the apprehension of Marco Tulio Carrillo Grande, a former Tijuana policeman who was believed to be working as the head of the Sinaloa cartel's hit men in Baja California.

Carrillo Grande is suspected of organizing deadly attacks on both the Jalisco cartel and the Arellano Felix organization, two organizations with which the Sinaloa cartel is vying for control of the Tijuana plaza, or trafficking territory.

Carrillo Grande "is identified as responsible for coordinating the aggressions of the criminal organization to which he belonged against a rival group with which [Carrillo Grande's organization] is disputing the Baja California zone, which has provoked the current spiral of violence in that region," Ramírez Gutiérrez said during a press conference.

Underworld alliances

Ramírez Gutiérrez's comments about a possible inter-cartel turf war are "the highest-profile claim yet made by a Mexican official placing CJNG in Baja California," according to Insight Crime, and come after reports earlier this year that escalating violence in Tijuana was related to cartel competition over territory.

Tijuana is just across the border from San Diego, and the two cities' border crossings are heavily trafficked. Google Maps

“Nueva Generacion does not have a significant physical presence in [Baja California, where Tijuana is located], but has focused on forging alliances with members of the Tijuana underworld in a challenge to the Sinaloa cartel,” Daniel de la Rosa, the public safety secretary in Baja California, told Sandra Dibble of the San Diego Union-Tribune in late February.

Tijuana’s homicide rate has jumped from 28 per 100,000 residents in 2012 to 39 per 100,000 in 2015, which made it the 35th-most-violent city in the world that year, according to a Mexican think tank.

Drug-related homicides were more than 536 of the city’s 670 homicides last year. Moreover, Dibble reports, 71 homicides in January were the most the city has seen in the first month of the year since 2010.

State officials were confident that the rise in killings (which has occurred alongside a drop in other common crimes) is the result of organized criminal activity — and of CJNG’s ambitions.

Violence has gone "up because a third group" that had not previously been in the city "is in the process of becoming established," the state’s deputy attorney general for organized crime, José María Gonzalez, told Dibble.

'There's the sense that … they're fighting'

The Sinaloa cartel — thought to be the most powerful trafficking organization in the world — and the Arellano Felix organization have competed for control over the Tijuana plaza for most of the last 20 years, with the Sinaloa cartel dominant for much of that time.

Soldiers stand guard outside the Attorney General's office in Tijuana June 4, 2011. Reuters

The arrival of the CJNG — one of North America's major meth traffickers — on the scene in the northwest Mexican city has the potential to increase the bloodshed, as the recent months have shown.

A relative newcomer on Mexico's narco scene, the CJNG emerged around 2010, reportedly from the remnants of a trafficking organization headed by Ignacio Coronel, an ally of Guzmán’s Sinaloa cartel (and reportedly Guzmán’s current wife’s uncle) in Jalisco state in southwest Mexico.

Since then, the CJNG has established itself as one of the most fearsome cartels in Mexico, seizing control of much of southwest Jalisco state, corrupting many police forces, and engaging federal and military forces in bloody shootouts.

Forensic workers stand over and around the headless body of a man in Tijuana October 12, 2010. REUTERS/Jorge Duenes

There have been rumors that CJNG and Sinaloa have cooperated to some extent. After Guzmán’s escape from prison in July, it was reported that CJNG had helped finance his escape.

While it has been hard to parse exactly what kind of relationship exists between the CJNG and Sinaloa cartels, rumors of CJNG expansion in to Sinaloa territory may be the latest development in a trend toward open conflict.

“It was usually thought they were collaborators, that Jalisco was a junior partner with Sinaloa,"said Alejandro Hope, the security and justice editor for El Daily Post, during a discussion at the Wilson Center in Washington, DC, in late January.

"But more increasingly there's the sense that they're rivals, and that … they're fighting, at least in some areas.”