U.S. Customs and Border Protection officers seized over $3.2 million in cocaine and methamphetamine hidden inside a gas tank of a commercial bus at the San Isidro, California, port of entry.

The seizure occurred on Sunday evening after a CBP canine team gave a positive alert on a commercial bus that was awaiting inspection, according to a U.S. CBP press release issued Tuesday night.

The driver of the bus was a 50-year-old Mexican citizen who was a B1/B2 visa holder.

CBP officers noticed anomalies in the gas tank and then pulled 98 packages from inside it. Forty-eight of the packages contained 200 pounds of cocaine with an estimated street value of more than $3 million. An additional 50 packages contained methamphetamine with an estimated street value of $182,000.

The driver was arrested and turned over to the custody of Homeland Security investigation agents for further processing. CBP officers put an immigration hold on the man so after he is processed judicially he will be returned to DHS custody.

“CBP officers remain vigilant and committed to halting the drug trafficking origination attempts to smuggle narcotics into the U.S.,” said Pete Flores, director of field operations for CBP in San Diego, in a prepared statement.

“CBP’s seizure of these narcotics sends a strong message that our efforts to stop illegal narcotics from entering our country will never falter,” said Flores.

In addition, CBP officers in Arizona at the Port of Nogales entry seized approximately $201,000 worth of heroin and methamphetamine on Monday morning, according to a CBP media advisory. The drugs were located within a speaker box of a smuggling vehicle and a narcotics-detecting canine alerted officers to the stash. The truck was driven by a 31-year-old Mexican man.

The driver was arrested and over to U.S. Immigration and Customs Enforcement’s Homeland Security Investigations.