A lengthy gunfight in central Mexico reportedly left 30 people dead last weekend, providing further — albeit mixed — evidence of a worsening security climate in the nation’s most populous state.

As reported by Mexican media outlets like La Jornada and Proceso, residents of the municipality of Luvianos, Mexico State, said that a shootout lasting more than an hour resulted in dozens of dead and wounded. Although security forces were unable to locate any of the bodies they hypothesized that the opposing criminal bands had each fled the scene with their dead. According to the initial reports, the fighting was between a local group and members of the the Familia Michoacana. State officials initially denied the news of the shooting, but days later Governor Eruviel Avila acknowledged that the gunfight had occurred, though he denied that there were any deaths or injuries among those involved.

The differing versions of this incident are difficult to reconcile. There are certainly precedents of government officials downplaying the intensity of gunfights in remote locales like Luvianos; one recent such example came in Choix, Sinaloa earlier this year. Yet turning a bloodbath that resulted in 30 deaths and that was already attracting the attention of national media into a minor and bloodless confrontation would seem a difficult, if not impossible, task.

In any event, the reports of severe violence fit with the recent publication of murder statistics by Mexico’s statistical agency, which reveals a worsening climate in the nation’s largest state. According to preliminary data released earlier this month by INEGI, the country’s statistical agency, the Mexico State saw 2,613 murders in 2011, second only to the border state of Chihuahua in the total number of killings. Put another way, nearly 10 percent of all of the murders nationwide last year occurred in the state; coupled with Chihuahua, the two states are responsible for 26 percent of all Mexican killings in 2011.

That is largely the product of a huge population rather than stratospheric murder rates, however. More than 15 million people live in the State of Mexico, which is known in Spanish as the Estado de Mexico and often referred to as Edomex. This translates to an annual murder rate of 17 per 100,000 residents, significantly below the nationwide average of nearly 25.

But the rise in killings is striking. The 2012 total represents a 110 percent increase over the 1,238 murders that the state registered in 2007 and a 24 percent jump from the 2,111 murders in 2010, in a state that is rarely talked about as a locus of criminal activity. The lack of attention to Edomex is partially explained by the enormous rises elsewhere; while the 24 percent leap in 2011 far outpaces the nationwide increase of 6 percent, the 110 percent jump since 2007 is outstripped by a more than 200 percent nationwide increase in murders over the same period.

Another factor limiting the concern over Edomex is that another major federal database, that of the National Public Security System, or SNSP for its initials in Spanish, shows a markedly different trajectory in recent years. The SNSP reported just 1,512 killings in 2011, more than a thousand fewer than INEGI. The two databases have long had discrepancies (Alejandro Hope wrote about the issue weeks ago), largely attributable to different ways of registering intentional and categorizing deaths. However, in recent years, the Edomax gap has grown far more gaping in recent years, and offers very different accounts of the state’s struggles with violent crime.

The alternate narrative present in SNSP figures has allowed Enrique Peña Nieto, the president-elect and governor of Edomex from 2005 to 2011, to point to security as a major area of success during his tenure. Indeed, as InSight Crime noted prior to his election, the SNSP stats allowed him to paint his state as an oasis of calm in a  country overwhelmed by drug-related violence. According to the SNSP figures, from 2007 to 2011, the state suffered an average of 1,279 murders a year, good enough for a relatively tame average rate of 8.5 per 100,000 residents. Moreover, the figure in 2011 is only 34 percent worse than in 2007, even as total murders in Mexico tripled. Such statistics offer a much more favorable backdrop for Peña Nieto than the INEGI numbers.

The rise in killings, whether it is the gentle upturn indicated by the SNSP or the more dramatic jump from INEGI, is largely attributable to ongoing rivalries between the swelling number of criminal groups operating in the region. Edomex has never been known as the exclusive turf of any of Mexico’s major cartels. In Mexico City, which is mostly surrounded by and many of whose suburbs lie in Edomex, these different criminal groups have long followed an unspoken truce, so that each gang enjoyed esentially unfettered access to the nation’s capital. As a result Mexico City and Edomex have been laregely spared the brutal battles for criminal control that have raged recently in place like Acapulco and Juarez.

Instead, the most active groups in Edomex have historically been local drug distributors. Among the most famous of these groups was the so-called Cartel de Neza or Ma Baker gang, which used to dominate the populous Mexico City suburb of Nezahualcoyotl. Recently though, several larger gangs have attempted to chase out their enemies and build a more substantial presence in the region. The Familia Michoacana has emerged as the most powerful gang in much of the state, including the municipality of Nezahualcoyotl.

But the group’s dominance is not unchallenged. Edgar Valdez Villarreal, aka “La Barbie,” operated in the region on behald of the Beltran Leyva Organization for several years prior to his 2010 arrest. Some of his erstwhile subordinates reconstituted themselves as La Mano con Ojos, which for a time in 2011 was among the most notorious groups in the state, and took to decapitating people associated with the Familia. Los Caballeros Templarios, a Familia splinter group steadfastly opposed to its old allies, operates in the state, and reports of the Zetas, perennial foes for all of the above mentioned groups, in Edomex have also grown more frequent.

None of these groups has been able to push the rest out, and the non-aggression pact that supposedly exists in Mexico City appears to hold little weight in much of the surrounding region. Should this dynamic continue, further troublesome data on security Edomex can be expected.