KANSAS CITY, Mo. (AP) — Kansas law enforcement agents are seeking an emergency ban on an easy-to-obtain synthetic opioid believed to have contributed to at least two deaths.

The Kansas Bureau of Investigation issued a warning last week about U-47700, which is not illegal in Kansas and can be purchased over the internet. KBI special agent Mark Malick called it an emerging threat that has no accepted medical use.

Johnson County District Attorney Steve Howe says it’s hard to pinpoint the number of deaths because the drug doesn’t immediately show up in post-mortem examinations. Two deaths in his county have been linked to the drug.

Ohio, Wyoming and Georgia have taken steps to ban U-47700, which is eight times more potent than morphine.

Howe says it might take until August to get a temporary ban.