Law enforcement officials say investigators in the Phoenix area have seized counterfeit pills that include carfentanil.
According to a press release from the Counter Narcotics Alliance (CNA), several hundred pills packaged for sale were seized. They are blue with markings that read "A-215."
"Carfentanil is 10,000 times more powerful than the equivalent dose of morphine -- 10,000 times more powerful," said Lt. Chris Wildblood with CNA.
This comes after Arizona officials confirmed the first carfentanil overdose in the state.
Carfentanil is not approved for human use in the United States, DEA agents say, and is only used for putting down large animals like rhinos or elephants.
The pills seized in Phoenix are known as "blues" or "Oxys," and are made to look like pharmaceutically produced oxycodone pills.
CNA is made up of some agencies including the Tucson Police Department, Pima County Sheriff's Department and U.S. Customs and Border Protection.
Lt. Wildblood with CNA says he thinks fentanyl has fueled the opioid epidemic. He had this to say about the crisis.
"It's about talking to your doctor about your pain and the medications you take," Lt. Wildblood said. "If you do take the medication, get them from a trusted pharmacy in the United States. Don't trust anyone else with your supply of drugs other than a pharmacist."
Lt. Wildblood also recommends that people should consider carrying Narcan if they or someone they know has an opioid use disorder. He says people should also seek treatment for substance abuse problems.