A train entering the United States from Mexico contained hundreds of thousands of fentanyl pills and other drugs, border officials said Wednesday. 

Officers with U.S. Customs and Border Protection were working rail operations when they searched a train coming into the Nogales, Arizona, Port of Entry.

During the search, they spotted a compartment in a spine rail car that contained 736,200 fentanyl pills and 196 pounds of methamphetamine, Port Director Michael Humphries said.

BORDER PATROL UNION PRESIDENT SAYS AGENTS FEEL ‘COMPLETELY DEFEATED’ AHEAD OF TITLE 42'S END

A day earlier, border officers at the port seized nearly 150,000 fentanyl pills hidden under the rear seat of a vehicle. On Monday, another 10,400 fentanyl pills and 6.4 pounds of meth were found inside tubes of construction adhesive placed among tools, authorities said. 

The seizures come as Mexican drug cartels continue to flood the southern border with fentanyl, U.S. Attorney for the Southern District of California Randy Grossman told Fox News Digital.

Worries about even more drugs coming into the United States come as the end of the Title 42 immigration policy draws near.

"We're going to continue to employ the strategy that we've been employing, which is aggressive prosecutions and prevention," Grossman said when asked about the possible end of the policy during a Tuesday interview with Fox News Digital. 

"We are very focused on making sure that we deter crimes at the border, including the scourge of fentanyl trafficking that's killing our residents, as well as preventing deaths in our community by getting into the community through an abundance of outreach programs in partnership with our law enforcement agency partners."

Fox News' Kelly Laco contributed to this report.