Updated

A county judge Wednesday ordered immunity from prosecution for anyone who turns in heroin or other potentially deadly drugs after a stunning surge in overdoses in the Cincinnati area.

Hamilton County Prosecutor Joe Deters asked for the blanket immunity, which he and Common Pleas Court Presiding Judge Robert Ruehlman agreed was unheard of locally, but needed to help get the drugs out of homes after what authorities say was a recent blitz of the city by sellers who mixed heroin with the extremely powerful animal tranquilizer, carfentanil.

"We may have family members who find it," Deters explained in court. "Their child may be an addict, their husband ... and this gives them a vehicle to turn it in without fear of prosecution."

Authorities have said nearly 300 overdoses have been reported in the Cincinnati area since Aug. 19, including 174 reports in a six-day period. The coroner's office has confirmed carfentanil, which can be thousands of times stronger than morphine and is used to sedate elephants, was present in at least eight overdose deaths in recent weeks.

"Turn it in, get it off the streets; get it out of your homes, out of your families," Dr. Lakshmi Sammarco said Wednesday, urging residents to turn in drugs that could be "extremely deadly."

Ruehlman's order covers anyone who "turns over any substance or combination of substances said person believes may cause the user of said drug to have an overdose." They can turn the drugs in to any law enforcement agency in the county.

Sammarco, Sheriff Jim Neil and other county officials accompanied Deters to court. She said earlier that the sudden spike in overdose cases raised concerns that heroin dealers were testing the community's response to carfentanil.

Communities in Ohio neighbors West Virginia, Kentucky and Indiana also saw overdose spikes in recent weeks.

U.S. Drug Enforcement Administration officials have said they believe much of the carfentanil is being shipped from China to Mexico, where traffickers mix it with heroin and other drugs such as the painkiller fentanyl.

Cincinnati firefighters said they sometimes had to use multiple doses -- as many as six -- of the overdose-reversal drug naloxone to save users during the spike. Authorities say carfentanil also poses danger to police, emergency personnel and drug dogs having contact with it.