Erie County Executive Mark Poloncarz has confirmed a deadly form of fentanyl is out on county streets.

He says on Monday alone, the Erie County Medical Examiner's Office has confirmed at least seven overdose deaths.

Poloncarz says those deaths occurred in the city of Buffalo and the Town of Tonawanda.

He says more information will be coming from the Erie County Department of Health.

This is a developing story and will be updated as more information becomes available.