Juha Korhonen of the North Savo Police says this is not the first time that fentanyl has been sold on the city's streets, but that this time the drug landed in inexperienced hands.
Police are trying to find out which part of the city fentanyl is being sold and remove it from circulation. Korhonen cannot estimate the exact amount of patches available on the black market, but says the substance is relatively uncommon in Kuopio. However, some prescribed fentanyl does filter through to illicit street sale, says Korhonen.
One person has died and two people are in critical condition in Kuopio, suspected of overdosing on the drug. Police warn that the drug may be ten times stronger than heroin.
Two people have also died of fentanyl overdoses in south-western Finland in recent weeks.