Guatemala's government declared a "state of siege" on May 11 in the Ixchiguán and Tajumulco municipalities of the San Marcos department near the border with Mexico, after an outbreak of violence between the inhabitants of both municipalities and security forces. According to a May 11 Interior Ministry press release, the state of emergency will be in effect for thirty days.

Interior Minister Francisco Rivas argued that the measure was necessary to disarm civilians in the area and restore the authorities' control, after the failure of more than a year of discussions with the belligerent parties, Prensa Libre reported.

For decades, the area has been subject to conflict between the communities of the two municipalities, initially over issues of land control and access to water. But levels of violence have spiked more recently, reportedly due in part to a fight for control of drug crops. According to both Prensa Libre and elPeriódico, the area is used for the cultivation of opium poppy, the base crop for making heroin.

This could explain why civilians appear prepared to protect their land with military-grade firepower. A video released recently by the Defense Ministry shows a shootout between soldiers and local inhabitants who seem heavily-armed. And authorities seized M-16, AK-47, and AR-15 assault rifles during a massive March police deployment.

Based on local testimonies, elPeriódico reports that the inhabitants of Tajumulco work for the Jalisco Cartel New Generation (Cartel Jalisco Nueva Generación - CJNG), while in neighboring Ixchiguán the opium poppy is destined for the Sinaloa Cartel.

InSight Crime Analysis

Guatemala has long served as the backyard of Mexican cartels. The Central American nation, an important transit area for South American cocaine heading north to the US market, was a strategic point for the Zetas, a Mexican crime group that succeeded in taking control of large swathes of Guatemala's drug trade until their decline after 2012. The Sinaloa Cartel, meanwhile, has long had an established presence in Guatemala where it likely remains the main buyer of drugs transiting through the country.

SEE ALSO: The Zetas in Guatemala

Meanwhile, Guatemala's opium poppy cultivation -- though difficult to estimate -- remains a concern for authorities. The latest International Narcotics Control Strategy Report from the US State Department notes that Guatemalan authorities recently began employing a new methodology to estimate opium poppy cultivation. The report states that the estimate using the new methodology showed a "dramatic increase over past estimates," but that "no independent data to support or refute this estimate."

In recent years, the Guatemalan government has attempted to tackle the opium issue through various measures, from forced eradication campaigns to crop substitution programs. However, authorities have struggled to control cultivation in the San Marcos department, the country's traditional poppy hub.

Additionally, reports that the communities of Ixchiguán and Tajumulco are engaged in a proxy war between the Sinaloa Cartel and the CJNG illustrate the effect of shifts in Mexico's underworld on criminal dynamics beyond Mexico's borders.

SEE ALSO: Coverage of Heroin

The CJNG has had a rapid rise to power in recent years, and the group is reportedly established in more Mexican states than the Sinaloa Cartel. In addition, various reports have pointed to territorial conflicts and power struggles between the two drug trafficking groups throughout Mexico.

With specific regard to the heroin trade, the US Drug Enforcement Administration said in 2016 that the CJNG (which is currently expanding its trafficking operations in the United States) and the Sinaloa Cartel are wrestling for control of the growing US heroin market.

Heroin overdoses, one indicator of overall consumption, have tripled within a decade in the United States, and opioid addiction is now routinely described as an "epidemic" in the United States. The booming demand for heroin has been blamed on massive over-prescription of legal opioid drugs linked to aggressive lobbying -- and allegedly criminal behavior -- by the US pharmaceutical industry.

Given this regional context, the conflict in Guatemala's San Marcos department appears to be just one battle in larger war for control of a lucrative illicit industry.