During Thursday evening, the police made a major effort in Sundsvall at several addresses.
Heavily armed police were involved in the operation.
The result of the operation is said to be several arrested people, as well as the seizure of weapons and narcotics.
Among other things, the police have made an effort at Södra Berget at Granmodalsgatan, according to information to SVT.
The police have a high presence in Sundsvall as a result of the extensive spiral of violence that hit Stockholm.
This is because there is a connection to the drug market in Sundsvall.
The operation was part of the police's intensive operation against criminal actors in Sundsvall, the police state on their website.
During Friday, prosecutors are expected to provide more information about the operation.
The case is being handled by prosecutors and no further information would be released Thursday night.