On Friday, one British Columbia city saw five people die of a drug overdose within a nine-hour period.
Police in Abbotsford, about 70 kilometres east of Vancouver, said three of the victims were men and two were women.
Four died inside apartment buildings and one was found outside a business. They ranged in age from 40 to 67, and all of them died alone.
Const. Ian MacDonald said that that many deaths in such a short amount of time is "absolutely alarming."
"It's become regular for first responders to attend overdoses, but to walk away from those where you've got five deaths … It's devastating on friends, family, community and first responders."
MacDonald said police have issued "countless" warnings about street drugs, but say substances being sold in the city seem to be "more deadly than usual."
"What we currently have on our streets is obviously more toxic and we need to let users know," MacDonald said. "The fact that these people died, generally speaking, indoors and alone isn't lost on us either and we need to sound the warning."
The officer said police hope that users take note of the fatalities and take measures to safeguard themselves if they use: carrying naloxone, taking less than a full dose and never using alone.
The BC Coroners Service says the number of overdose deaths in B.C. this year has surpassed the total number of deaths in all of 2016.
In the first eight months of 2017, 1,013 people died from a suspected illicit drug overdose. That number was 922 in 2016.
Police said it will take time for toxicology testing to determine whether fentanyl or carfentanil contributed to the deaths in Abbotsford on Friday.
The coroner estimated that 90 per cent of illicit drug overdose deaths take place inside private residences.