Clashes between Mexican troops and gasoline smugglers leave at least 10 people dead, including four soldiers, in Puebla state, said Mexican officials May 4. The incidents took place May 3 between Mexican law enforcement authorities and fuel smugglers known as huachicoleros.

The clashes occurred in the town of Palmarito Tochapan, which is part of the municipality of Quecholac that authorities call the “red triangle” of fuel smuggling. Authorities say pipeline theft gangs practically control some regions and work with corrupt police and politicians.

The smugglers and their supporters attacked military forces, who were responding to reports that thieves had breached a pipeline. Around 1,000 troops were sent to suppress the violence. The 10 people who died during the clashes were four soldiers and six “presumed criminals,” said government secretary in Puebla, Diodoro Carrasco, to reporters.

Among the casualties according to officials, more than a dozen people were injured, and Carrasco said there were 14 suspects in the attacks arrested. Officials also accused smugglers of using children and women as shields during the altercations.

The smugglers are known for taking fuel from pipelines belonging to the state-owned Petroleos Mexicanos, or Pemex, and selling it on the black market, in plastic containers along roadsides. The military has been called to fight against the massive gas-smuggling industry, which has cost the financially troubled Pemex hundreds of millions of dollars a year in lost revenue, according to a report from the Los Angeles Times. Yet, according to officials, families have come to rely on the smuggling enterprise.

Analysts say the smugglers work with narco-gangs, like the ultra-violent Zetas, who are a major presence in the oil-producing Gulf Coast state of Veracruz which borders Puebla, a hub of the gasoline-pilfering industry. While the huachicoleros have been stealing fuel for more than a decade, authorities said its increased since gas prices have risen this year.

Despite this, civilians are protesting the army, blaming them for the clashes and casualties, one person carried a banner saying, “We don’t want the military to attack us.” The military responded saying it acted appropriately to the situation and vowed to continue cracking down on the fuel thieves and the entire huachicolero industry.

“These operations against illegal [pipeline] taps will not only continue, but will be more frequent,” said Tony Gali, governor of Puebla. “This criminal presence is poisoning families [and] children. We saw women and children being used as shields by these cowards.”