Acting on a tip, Mexican soldiers seized almost 1.5 tons of meth and 328 pounds (149 kilograms) of apparent powdered fentanyl at a checkpoint in the northern border state of Sonora, the army said Thursday.
Soldiers also found 816,486 pills apparently containing fentanyl packed in 46 drums aboard the truck on Wednesday.
The Defense Department said it obtained information that a truck carrying powdered fruit juice concentrates to the border city of Tijuana was also hauling drugs.
Mexican cartels frequently pass officials information on shipments owned by rival gangs.
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Mexican cartels manufacture fentanyl, a synthetic opioid, from precursors imported from China. They then press the drug into counterfeit pills made to look like Xanax, Adderall or Oxycodone.
Synthetic opioids like fentanyl have been behind a major increase in overdose deaths in the United States. As little as two milligrams of fentanyl can be lethal. The drug is 100 times more potent than morphine.
People taking the counterfeit pills often don't know they are consuming fentanyl. That has contributed to the rise in overdose deaths.