Police in Sarnia, Ont., have issued a public safety notice after one person died and two others were taken to hospital on Wednesday evening due to suspected drug overdoses.
Police say the drug involved was thought to be cocaine but is now believed to have been laced with the dangerous opioid fentanyl and are asking anyone who recently bought street drugs to not use them due to the possibility of an overdose.
Residents are also being urged to "not be afraid" to call 911 in an emergency and state what drugs were involved so first responders can provide the proper course of treatment.
Police say the three overdoses occurred over five hours.
Many Canadian cities have grappled with drug overdose deaths in recent months, perhaps the most notable being Vancouver, which recorded 25 deaths and nearly 600 overdose calls in June alone.
More than 1,000 people died of overdoses in British Columbia last year and the coroner says fentanyl was involved in many of those deaths.
Toronto police had issued a public safety alert last month after four people died of suspected opioid overdoses over three days.