Durham Regional Police say fentanyl may have been involved in seven drug overdoses in Whitby and Oshawa this weekend.
Three men aged 18 to 20 ingested cocaine at a Cullen Gardens gazebo that Durham police believe may have been laced with fentanyl.
All three were unresponsive and two of the men were given Naloxone on the way to the hospital to regain consciousness. The men are expected to survive.
Three other males ingested cocaine on Friday night in Oshawa, with one becoming unconscious, and a seventh male was also rushed to hospital after overdosing on cocaine on Saturday.
Durham police are now investigating if the cases are related.
They add that they are urging parents to speak with their teens regarding the dangers of drugs. There are no guarantees that drugs have not been mixed with other substances like fentanyl.