Last month border agents in Arizona intercepted a shipment of approximately four million fentanyl pills in the largest seizure of the narcotic in the history of U.S. Customs and Border Protection (CBP), the agency announced on Thursday.

According to CBP, on July 1, officers at the Lukeville, Ariz., port of entry stopped a pickup truck hauling an SUV on a utility trailer driven by a 20-year-old U.S. citizen for an inspection.

With assistance from a CBP canine team, officers discovered “anomalies” in the frame of the trailer and found 234 packages of drugs concealed within the frame of the trailer, CBP said.

A total of four million blue-colored fentanyl pills, weighing more than 1,000 pounds, was seized — the largest seizure of fentanyl in CBP history.

“This is the largest fentanyl seizure in CBP’s history, and reflects our unwavering determination to protect our nation and to disrupt the criminal activities of ruthless drug cartels,” acting CBP Commissioner Troy Miller said Thursday.

“Every day, CBP officers and agents are on our front line, using their keen instincts and the latest technology to prevent deadly drugs from entering our country and poisoning our communities,” Miller said.

Within two weeks of the July 1 seizure, CBP officers at the same port of entry also intercepted 270 pounds of methamphetamine being smuggled across the border by a 45-year-old Mexican citizen.

CBP estimated the total street value for the two seizures at over $12.6 million.

“This is an enormous amount of dangerous drugs that officers at the Port of Lukeville prevented from reaching communities throughout the United States,” Director of the CBP’s Tuscon Field Office Guadalupe Ramirez said.

In fiscal year 2024 to date, CBP has seized over 211,000 pounds of illegal drugs at the U.S.-Mexico border, including more than 124,000 pounds of methamphetamine and 14,500 pounds of fentanyl.