Deaths in what the Mexican government calls "confrontations and aggressions" rose from 231 in 2007 to 2,099 in 2010 (see statistics here). Figures for 2011 are not yet available but one government official, speaking on condition of anonymity because he is not allowed to comment publicly on this matter, said there have been over 950 deaths in "confrontations" through early June 2011, suggesting that they will equal or surpass last year's totals.

"Confrontations" and "aggressions" are two of three descriptions the Mexican government uses to categorize deaths related to organized crime. Unfortunately, the government groups these two categories together in its statistics, but they are decidedly different.

"Confrontations" refers to skirmishes between authorities and suspected criminals, or between criminal groups. "Aggressions" happen when a group attacks a government installation, for example, with a grenade. In an "aggression," the security forces do not respond.

The third category is "executions," which is how the authorities define murders in which, for example, there are signs of torture, the victim has a criminal past related to organized crime, the body has been moved, there are multiple bodies, and other signs that organized crime was involved. (Download government methodology here.)

Deaths due to "executions" still far surpass those in "confrontations and aggressions." According to government data, there were 13,174 "executions" in 2010, out of a total of 15,273 total deaths.

But the sharp rise in "confrontations and aggressions" means both large criminal organizations and their Mexican military counterparts are taking the fight to a new stage.

Most of these appear to be concentrated in the northeast corner of the country -- Tamaulipas, Nuevo Leon and San Luis Potosi -- where in the first two months of this year, authorities registered 338 deaths of "aggressors" (the term the government uses for the suspected members of organized criminal gangs) through April 27.

The two highest jumps in the number of deaths in "confrontations and aggressions" are in the states of Tamaulipas and Nuevo Leon, the troubled northeast border where the Gulf Cartel and their former proteges, the Zetas, are battling for control. (See different displays of these statistics in Google Fusion.)

These two groups employ military tactics. In the last year, for instance, both have used rocket propelled grenades (RPGs) and refitted large trucks with with armored plates and turrets.

As InSight Crime has noted, the so-called "narco-tanks" speak to both these groups' military precedents and their current strategies of head-on confrontation with each other and the state.

But while these narco-tanks have caused a stir, they are still no match for the army, which has sent thousands of troops to the area.

Tamaulipas, in particular, has seen deaths due to "confrontations and aggressions" rise substantially, going from 7 in 2007, to 638 in 2010, surpassing the rate of "executions" -- the only state where this has happened.

Mexican President Felipe Calderon has repeatedly defended the military's actions.

"The problem comes when they are firing at you with rocket propelled grenades, like what is happening in Tamaulipas," he told Televisa's Denise Mearker in 2010. "There is very little time to react, and so the clashes become more violent every time."

But a closer look at the "battles" in Tamaulipas since the beginning of 2010 shows a decidedly one-sided affair.

InSight Crime compiled a list of all the incidents that the Mexican military has registered (in public communiques) in the state of Tamaulipas since the beginning of 2010 through the end of July 2011. During that time period, the army said it had killed 267 "aggressors," arrested 137, and had 34 casualties, including 3 dead. (Download .pdf list of events and links to the army's press releases here.)

It is possible that the military was hiding the number of casualties; the army, in particular, is known for under-reporting its own body count. But media petitions to get such information, such as that by Milenio news organization, revealed total deaths for the army to be 105 between December 2006 and June 2011, in the entire country. Oddly, the army said later that 191 military personnel had been killed.

In either case, it is far below the number of "agressors" killed. Among these events in Tamaulipas, two cases in Ciudad Mier in September 2010, which left an estimated 47 "aggressors" dead and 4 army soldiers injured, stand out.

Ciudad Mier was a war zone last year, as this excellent two-part series in Gato Pardo illustrates. The Gulf Cartel and the Zetas, both of whom draw heavily on ex-military personnel to fill their battle units, were fighting block by block.

The city is in the strategic corridor connecting the country's second largest city, Monterrey, to the Frontera Chica -- the short strip of land where Gulf and Zetas send drugs and migrants and receive weapons and cash. In other words, it's at the heart of the struggle

This Gulf-Zetas fight had been brewing for years, but started in earnest when the Gulf killed a Zeta commander in January 2010, and refused to hand over the assassins. In the Mexican underworld, this was akin to the murder of Archduke Franz Ferdinand; war erupted throughout the country.

Still, "battles" that leave 47 dead on one side raise red flags, even more so when they happen in contested areas where questions about conduct can be easily deflected with a "fog of war" argument.

The army's comuniques (available here and here) about these confrontations offer little: four short paragraphs describing an attack by the "aggressors," a response by the army, and then a list of the results, including the number of dead "aggressors." The news reports on the incidents are repeats of the army's assertions. There is no independent confirmation of what happened in either incident.

The Mexican Attorney General's Office (Procuraduria General de la Republica - PGR) does not have the mandate to unilaterally investigate such cases. Even a celebrated recent ruling by the Supreme Court that calls for cases involving "human rights violations" to be remitted to civilian courts is unlikely to change the PGR's practice of remitting them to the military.

When asked about the incidents in Ciudad Mier, the Mexican military, known by its acronym SEDENA, referred InSight Crime to the "competent organization" in charge of investigations. The PGR, the presumed "competent organization," did not respond to repeated attempts by InSight Crime to discern whether they were investigating any case involving the military.

Mexico's National Human Rights Commission (Comision Nacional de Derechos Humanos - CNDH), one of the few Mexican government entities looking into army abuses, has received 5,055 complaints against the army since Calderon took office in December 2006. Of these, 4,389 have been "resolved," according to the army, which also likes to insinuate that organized criminal gangs are part of a disinformation campaign.

One case that has not be resolved, however, was the death of two children, ages five and nine, who were killed April 3, 2010, by military personnel. The CNDH said the army altered the scene of the crime. SEDENA still claims the two children were killed by shrapnel from a grenade tossed by traffickers during a skirmish.

The case drew attention because of the age of the victims. Most cases never get that far, and the victims remain nameless and faceless.

Human Rights Watch (HRW) has chronicled several military cases in which army personnel killed or disappeared civilians, including eight suspicious deaths in the state of Nuevo Leon. But other cases, such as the Ciudad Mier battles, have been buried.

"Human Rights Watch has documented cases across several states of soldiers manipulating crime scenes after shootouts, as well as other evidence that strongly suggests the practice of extrajudicial killings is not isolated," Nik Steinberg, HRW's Mexico Researcher, wrote to InSight Crime in an email. "Yet when killings are investigated at all -- which is rare -- it is by military prosecutors who consistently fail to undertake the most basic investigative steps, such as interviewing witnesses. As a result these crimes go unpunished, and victims' families are denied the justice they deserve."

For its part, the United States Government, which is providing millions in aid to Mexico under the Merida initiative, has been relatively silent, highlighting the most egregious cases in its annual human rights report. But neither congress or President Obama has pressed the Mexican government much in public.

Amidst all the carnage, there is a deeper question that few are asking: Could this trend be the result of an increase in extrajudicial executions by the military?

This was the theory one former Mexican intelligence official put forward to InSight Crime. With the death toll skyrocketing and the Mexican justice system floundering and in flux, frustration is rising, the former official said, leading some to take the expedient option.

There is no evidence of a systematic extermination of the enemy. But David Martinez-Amador, a social sciences professor and expert on crime, says he believes the army is resorting to extreme measures.

"Because the Mexican system is weak and corrupt, it is cheaper for the State to simply whack every single 'potential' sicario," he told InSight Crime in an email exchange.

The situation is reminiscent of Colombia, a country that is no stranger to military abuses. Authorities and media, such as InSight Crime's Spanish language partner Verdad Abierta, have chronicled the connection between military personnel and right-wing paramilitaries who worked for two decades at "cleansing" (i.e., exterminating) the country of suspected guerrillas and their potential collaborators, killing by the thousands.

In Mexico, there are certainly paramilitaries in the making. One such group is the so-called "Matazetas" (Zeta Killers), a faction of the New Generation Jalisco Cartel (Cartel de Jalisco Nueva Generacion - CJNG), which claimed in a recent video they would eliminate the "injustice" of the Zetas in the state of Veracruz.

Professor Martinez noticed the the armed men in the video held their weapons in military style, placing their fingers near but not on the trigger.

"This particular video showing the "Mata-Zetas" unit of the New Generation Jalisco Cartel is either a group of former Mexican military or a paramilitary group," the professor told InSight Crime.

Just as significant, perhaps, is that the group urges people to denounce the Zetas' transgressions to the Mexican Marines and SEDENA, "the only institutions that have not been corrupted."

The Colombian government is also investigating thousands of deaths termed "false positives," a euphemism for the military's penchant for killing innocent civilians, then dressing them up as rebel fighters in order to show results for the demanding then-president.

The Mexican government has depended on similar "results," claiming that bodies equals advancement of its agenda to weaken the enemy.

But Calderon has also shown a keen understanding of the tricky balance between respecting human rights while not backing down in the face of the enemy.

"It's a difficult equilibrium," he said in the Mearker interview. "But it's critical. The State must be morally superior.

"I'm not going to say there haven't been abuses, there haven't been errors, mistakes," he added. "But that's the order the military has."

For the moment, it may not matter. A poll released this week by the National Autonomous University (UNAM) said that only 54 percent thought it was possible to respect human rights in the battle against organized crime. What's more, according to the poll, the army has the highest level of confidence of any Mexican institution.

*Jen Sokatch and Patrick Corcoran assisted in reporting this story.