Durham Regional Police say officers have responded to 11 overdoses since Thursday, including one that was fatal.
The service says many of the overdoses involved cocaine, heroin or fentanyl.
The drugs have been sent to lab for testing, with some appearing to be a mix of fentanyl and another drug.
Officers were able to use the overdose-reversing drug Narcan to save a number of people.
Durham police call the number of incidents an “unusually high trend.”
They are warning against illicit drug use and improper use of medication.
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