The health agency says what happened is concerning but that it's not uncommon for a large number of people to overdose in one day because of the contamination of street drugs with synthetic opiates, such as fentanyl.
Montreal's ambulance service says it received a call Sunday afternoon for six people experiencing overdoses and that four were transported to hospital. Urgences-santé spokesman Sébastien Coulombe says a second call was received from the same area slightly over an hour later and that two additional people were sent to hospital.
Montreal police say five of the six people transported to hospital are out of danger and that one person remains in critical condition. Heather Johnston with Projets Autochtones du Québec, which operates a shelter for Indigenous people in downtown Montreal, says six of the people who overdosed were staying at the centre.