Two people are dead and four are in hospital following drug overdoses police believe involved cocaine possibly laced with fentanyl.
Police have also issued a public safety advisory. Investigators have now charged 10 people with numerous drug-related offences, and three people were arrested on outstanding warrants, followed by the unconditional release of six people who were known to police.
Saskatoon police have asked anyone who may have bought the drugs to hand them into police - and have said buyers of the laced drugs won't be charged for doing so.
But he said paramedics are never sure exactly what drug is responsible for a overdose and they always take precautions.
The first one was on Murphy Crescent at 7:30 a.m.
Responders were called to a third home at 10:30 a.m.
The three men were scheduled to appear before a justice of the peace Sunday evening to face drug and weapon charges.
Over in the United Kingdom, fentanyl has also been linked to a number of deaths, including 18-year-old Robert Fraser from Kent.
A 46-year-old Pickering man has been charged with: possession of cocaine for the goal of trafficking and possession of a controlled substance (cocaine). One of the two died with the other recovering.
A 25-year-old woman, a 28-year-old woman, a 30-year-old woman, a 35-year-old man, a 41-year-old man, and a 50-year-old woman, all from Barrie, have since been charged.
Police have arrested three men in connection with the case.
A 41-year-old Barrie man has been charged with: possession of cocaine for the objective of trafficking and possession of a controlled substance (cocaine).
Between the arrests and the search, police say they seized more than $14,000 in cash, 11.16 grams of cocaine/fentanyl, 149.88 grams of cocaine, 31.13 grams of heroin, and 34.44 grams of marijuana, a firearm and ammunition.
They have released the name and phone number of an alleged drug dealer in hopes of preventing further casualties.
Police added that they are "not searching to pursue charges for being in possession of this cocaine" and that they are only interested in the public's safety.