Health officials in Illinois and Indiana say a new synthetic opioid appears to be linked to some overdose cases, USA Today reports. The drug, isotonitazene, was mixed with cocaine.

Isotonitazene comes in a white or off-white powder form or pressed into counterfeit opioid pills, the article notes. It is not a fentanyl analog. The drug is sold online and appears to be entering the United States from abroad, according to Dr. Mine “Mike” Kalfas, an addiction specialist in northern Kentucky.

The drug is not yet on the U.S. Drug Enforcement Administration’s list of controlled substances, which means it is not illegal.

Canadian police seized 1,900 isotonitazene tablets from a home in Halifax, Nova Scotia in February.