Agents discovered the shipment Friday at the airport in Guadalajara, Mexico’s second-largest city, the Defense Department said in a statement.

They confiscated about 100 pounds (50 kilograms) of crystal methamphetamine, 60 pounds (30 kilograms) of heroin and 20 pounds (10 kilograms) of methylphenidate, which is often used to cut heroin, according to the statement. There were no arrests.

The Defense Department did not say how the drugs were discovered or give further details on the shipment.

Phone calls to Aeromexico representatives rang unanswered Saturday.

Tijuana, across the border from San Diego, is a major staging point for funneling drugs into the United States.