McALLEN, Texas — Members of Mexico’s Gulf Cartel are deploying teams to various stores in this border city area to purchase bulk quantities of ammunition for smuggling back to Mexico. It remains unclear if the reported stockpiling attempts could indicate a coming escalation in violence in across the border in Reynosa.

In recent days, agents with U.S. Homeland Security Investigations and the Bureau of Alcohol, Tobacco, Firearms, and Explosives arrested six individuals allegedly connected with at least three separate attempts to purchase and smuggle thousands of rounds each.

In the border city of Reynosa, Mexico’s Gulf Cartel is waging a fierce war for control of lucrative drug and human smuggling territories. The fighting, carried out by two warring Gulf Cartel cells, led to weeks of large-scale gun battles that spread terror and caused more than 260 confirmed murders.

In one of the investigations, HSI agents arrested Edgar Ivan Santiago, Jazmin Vianey Lopez, and Sarahi Gomez Hernandez after the alleged attempt to smuggle 1,000 rounds for AR-15 rifles; 700 rounds for AK-47 rifles; 200 rounds of 9mm; 100 rounds of .300 blackout ammunition; and several magazines. The group reportedly crossed into the city of Hidalgo through an international bridge and visited several local stores, purchasing the boxes of ammunition. As part of an ongoing investigation, agents followed the group to a stash house in Pharr, Texas, before heading back to Reynosa. Authorities arrested the group as they attempted to cross into Mexico and raided the house.

In a similar case, Osvaldo Diaz Villarreal, a Mexican citizen, reportedly purchased more than 2,000 rounds for AK-47 rifles. Federal agents carrying out surveillance saw Diaz Villarreal pick up the ammunition and detained him in north McAllen. The man reportedly told agents that he purchased the ammunition for $638. Since Diaz Villarreal is a Mexican citizen on a tourist visa, he is not able to legally purchase ammunition.

Federal agents also arrested Eduard Vasquez in the border city of San Juan. According to court records, HSI agents learned that Vasquez purchased at least four rifles and one handgun for smuggling into Mexico. During questioning, Vasquez told agents that he received $600 for the weapons on behalf of cartel members.

Ildefonso Ortiz is an award-winning journalist with Breitbart Texas. He co-founded the Cartel Chronicles project with Brandon Darby and Stephen K. Bannon. You can follow him on Twitter and on Facebook.

Brandon Darby is managing director and editor-in-chief of Breitbart Texas. He co-founded the Cartel Chronicles project with Ildefonso Ortiz and Stephen K. Bannon. Follow him on Twitter and Facebook. He can be contacted at bdarby@breitbart.com.