CINCINNATI, OH (WLWT) — Synthetic opiates like fentanyl have been found in marijuana, Hamilton County Coroner Dr. Lakshmi Sammarco confirmed to NBC affiliate WLWT-TV Monday.

Fentanyl, a drug 50 to 100 times more powerful than morphine, has been linked to a surge of fatal overdoses across the county. It has been showing up in other drugs across the area.

“We have seen fentanyl mixed with cocaine, we have also seen fentanyl mixed with marijuana,” Sammarco said during a joint press conference with Sen. Rob Portman.

Sammarco said that there have already been 297 deaths in Hamilton County this year caused by suspected opioid overdose, compared to 403 confirmed deaths in all of 2016.

She did not specify how many cases involved marijuana mixed with a synthetic opiate.

“Essentially, the message we’ve tried to get out there, is if you are using any form of street drugs, count on them having some form of synthetic opioid mixed in,” Samarco said.

Samarco added that it is nearly impossible to tell which drugs are mixed with a synthetic opiate.

“We can’t tell you for sure until we test the blood of someone who has died or any of the drugs seized by law enforcement,” she added.