Authorities say a potentially "lethal" batch of heroin appears to be circulating in the Evesham Township area of South Jersey.

At least four overdoses were reported in the Burlington County township in just the past 24 hours, said Lt. Joseph Friel of the Evesham Township Police Department Saturday night.

Friel said all four of the victims were revived after receiving a dose of naloxone, the drug used to reverse the effects of opioid overdoses.

Authorities were prompted to issue their warning on a weekend evening, Friel said, because of the sudden spike in overdose cases.

What was described as a "bad batch" of heroin in rural Salem County claimed at least three lives in January.

Friel said anyone who knows of someone experiencing a heroin overdose should call 911 immediately to get help for them.

He says New Jersey's Good Samaritan Law protects those from arrest, who in good faith, seek for help for themselves or someone they see experiencing a drug overdose.

Bill Gallo Jr. may be reached at bgallo@njadvancemedia.com. Follow Bill Gallo Jr. on Twitter @bgallojr. Find NJ.com on Facebook. Have a tip? Tell us. nj.com/tips