Montreal police believe drugs laced with the deadly drug fentanyl are responsible for seven overdoses in the neighbourhood of Hochelaga-Maisonneuve earlier this week.
Police have carried out a series of raids following the overdoses, which occurred between Thursday night and Friday.
They believe the drugs linked to the overdoses originated from the same sellers, and that the drugs may have been cut with fentanyl.
Five people have been arrested in connection with the investigation, and police are currently searching for a sixth suspect, a 30-year-old man.
The overdoses were not fatal, but police say they had to act fast to intercept the drugs.
"It was really, really, really dangerous," said Const. Manuel Couture.
By Friday night, police raided two apartments in Montreal. The raids led to the seizure of several drugs — including 260 grams of what's believed to be a mixture of heroin and fentanyl.
More people being trained to treat overdoses
SOS Itinérance, a group that helps Montreal's homeless, has recruited volunteers to administer Naloxone, a drug used to treat a narcotic overdose. The community group Dopamine does the training.
The head of the group, Alexandre Paradis, said they were called to several of Friday's overdoses. On Saturday, they held an emergency training session to prepare more volunteers to administer Naloxone.
"We saw there's a big wave of usage in this moment, we're trying to train as many people as possible," said Paradis.
Police are waiting for lab results to confirm what substances were in the drug mixture.