Law enforcement officials are warning about a spike in overdose deaths connected to counterfeit Xanax in Pinellas County.

Nine people died from overdoses between January and March, officials said during a news conference Monday. Three of those deaths are the result of counterfeit Xanax pills bought on the street, officials said.

Officials said the cause of death was a lethal mixture of Xanax and Fentanyl.

Fentanyl is a drug commonly used with cancer patients to relieve pain. Sheriff Bob Gualtieri said Fentanyl is "80 times more potent than morphine and about 50 times more potent than pure heroin."

Officials said they strongly suspect six overdose deaths to be related to the same type of counterfeit Xanax/Fentanyl pills.

The overdose deaths have all taken place from Largo south to St. Petersburg.

Investigators said they've recovered similar counterfeit Xanax/Fentanyl pills in nine cases throughout the county and that those pills were produced to imitate the same size, shape and markings as Xanax pills.

They said they don't know where the counterfeit pills are coming from, but that right now, it appears as though they are limited to Pinellas County.

Officials warn people to use only pills that have been prescribed by doctors and purchased through a pharmacy.

Officials said another three overdose deaths happened between October and January and that those deaths were attributed to the drug U-47700, which is an opioid painkiller.