Drugs were recently seized by authorities in Ontario that had the appearance of cannabis but was actually found after testing to contain carfentanil and cannabis, Guelph Police said in a public alert.

A similar product was also found in Ohio that contained heroin and fentanyl. These have yet to be found within the city borders of Guelph at this point but a warning was given in a police statement.

Opioids such as fentanyl and carfentanil cannot be detected by sight, smell or taste, police warn, and overdose can occur via inhalation, ingesting or injecting.