Shortly after 8 a.m. April 24, a pickup truck erupted into flames while parked outside a government office building in Nuevo Laredo where the state's attorney general has an office. It appears that gas tanks placed in the bed of the truck were rigged to form an improvised incendiary device.

While media reports have called the incident a "car bombing," images of the scene indicate that the body of the truck sustained heavy fire damage, rather than the explosive damage characteristic of a car bomb, technically referred to as a vehicle-borne improvised explosive device. The device appears to have caused little damage to anything other than the truck. If anything, a small explosive device, known as an explosive actuated incendiary device, may have been used to ignite the fuel.

The explosion triggered a response from the local military unit, which then cordoned off the area in front of the office building. After the explosion, gunmen appeared and opened fire on the responding military personnel. No military personnel were killed or injured in the ambush, but two bystanders were injured. The explosion appears to have been intended to draw the military into an ambush and send a message that they are easy targets.

Using improvised explosive and incendiary devices to bait authorities is not a new tactic in Mexico. We have seen similar small-scale devices used in attacks and ambushes in Monterrey, Ciudad Victoria and Ciudad Juarez.

However, the April 24 attack was bolder than usual because it occurred outside the attorney general's office and targeted military personnel — not just police or medical responders who have more often been targets in the past.

A few hours after the attack, a narcomanta claiming the attack on behalf of elements affiliated with the Sinaloa Federation appeared near the scene. The Sinaloa Federation and its allies have been increasing activity in Nuevo Laredo in an attempt to wrest control of the city from Los Zetas. Nuevo Laredo is considered strategically valuable since it is a port of entry into the United States. Stratfor has been following this trend since March, when seven dismembered bodies accompanied a narcomanta claiming Nuevo Laredo belonged to the Sinaloa Federation.

This is not the first time that the Sinaloa Federation has attempted to take control of territory in Nuevo Laredo. The group previously made a move on the city while it was under the control of the Gulf Cartel — Los Zetas' parent organization. Following the arrest of Gulf Cartel leader Osiel Cardenas Guillen in 2003, the Sinaloa Federation saw an opportunity to move in while the Gulf Cartel was weak and gain control over the city. In the years since that attempted incursion, violence has increased dramatically, as have the displays of violence including beheadings and body dumps in public squares.

While a vehicle exploding just miles from the U.S.-Mexico border makes for alarming and dramatic news stories, the general state of escalating violence along the border is a more serious threat. Both Sinaloa and Los Zetas can bring significant resources to a conflict over valuable territory. However, drug traffickers are only one group of many that use Nuevo Laredo as a port of entry; thousands of U.S. and Mexican businesses trade across the border every day.

The April 24 attack alone will not necessarily affect broader trade activity in the region, but it does fit into a series of escalating attacks by an entrenched Los Zetas force, a looming Sinaloa Federation force and the military caught in between. This trend could mean more violence and disruptions in the near future.