NOGALES, Ariz. (NewsNation) — It’s the U.S. Customs and Border Protection (CBP) against the cartel in a deadly game of cat and mouse playing out at Arizona’s Nogales port of entry. 

X-rays and expertly trained K-9 units are the keys to locating the deadly drugs that smugglers are trying to bring into the country by any means necessary.

CBP officers told NewsNation they regularly see vehicles with drugs inside the seats, the dashboard and tailgate. But now, smugglers are getting more creative; pills have been found stashed in hollowed-out car batteries.

CBP says 85% of the drugs seized along Arizona’s border are confiscated by Office of Field Operations officers while Border Patrol agents in the field seize 15%.

In six weeks, 855 pounds of methamphetamine and more than 4.3 million fentanyl pills were seized at the Nogales port of entry, but millions of pills are still making it into the interior of the U.S. The U.S. Drug Enforcement Administration (DEA) has warned of the rainbow-colored fentanyl pills and claim the drug is already present in 18 states.

The port’s director, Michael Humphries, said despite the technology and the resources, officers don’t have the capabilities to stop every vehicle.

Fentanyl has become the leading killer of Americans ages 18 to 45. The DEA has said two milligrams of the drug can be deadly.