HILLSBOROUGH, N.C.  — An investigation is underway after two kilograms of fentanyl were seized in an operation in Hillsborough, according to the Orange County Sheriff’s Office.

Deputies recovered the drug during an enforcement operation they were conducting with other state, federal and local law enforcement partners, authorities said.

The suspected fentanyl was seized during the operation and sent to a lab for testing. Testing has since been completed and the sheriff’s office has been able to confirm that the seized product was, in fact, fentanyl.

Fentanyl is a synthetic opiate that has been the cause of numerous accidental and incidental overdoses across the country, the sheriff’s office said. The synthetic opiate isoften added to, or represented as, heroin.

Authorities said that if anyone encounters a substance that they believe has fentanyl in it, they should not handle it and immediately call law enforcement.

Because the investigation is ongoing, the sheriff’s office is not able to release any more information.