PHOENIX (AP) — U.S. Customs and Border Protection officials announced Thursday their biggest fentanyl bust ever, saying they captured nearly 254 pounds (114 kilograms) of the synthetic drug that is fueling a national epidemic of fatal opioid overdoses from a secret compartment inside a load of Mexican produce heading into Arizona.

The drug was found hidden Saturday morning in a compartment under the rear floor of a tractor-trailer after a scan during a secondary inspection indicated "some anomalies" in the load, and the agency's police dog team alerted officers to the presence of drugs, Nogale...