U.S. Customs and Border Protection seized almost $2 million worth of narcotics from two 18-year-old Arizona residents near the Mexico border, NBC News reports.

Border Patrol agents arrested the teens on Saturday after people were spotted appearing from some brush to leave packages in a parked truck. It was later discovered that the packages contained methamphetamine, cocaine, and heroin that were worth an estimated $1.8 million, according to  U. S. Customs and Border Protection.

“We've gotten larger seizures, but this one no doubt is sizable, and it is significant,” Border Patrol agent Daniel Hernandez said in a statement. “The street value is pretty high.”

The teens were handed over to the Drug Enforcement Administration federal charges, and are expected to face federal charges. Their identities have not been released. Border Patrol wasn’t able to find the people who appeared from the brush to hand over the packages.

It’s not abnormal for people to travel on foot from Mexico into the U.S. in order to deliver drugs and go back to Mexico. These people are typically hired by transnational criminal organizations.

That part of the border is usually known as a marijuana corridor, according to Hernandez. “That is declining, and now we're seeing with greater frequency harder narcotics and synthetic narcotics,” he added.