An ambulance parked at St. Boniface Hospital had vials of narcotics stolen early Monday morning.
The thefts occurred at around 3 a.m. and included two vials of midazolam and four vials of fentanyl.
The Winnipeg Fire Paramedic Service says taking the drugs without medical supervision can be dangerous or fatal.
Police are investigating the theft and ask anyone with information to contact them at (204) 986-6219.
The WFPS is conducting its own internal investigation of the incident.