Police barriers remained in place in the area on Sunday but were not expected to affect traffic significantly and have since been lifted, with examination of the location completed.
An explosion at the site was reported to police at 4:23am on Sunday, a spokesperson told TT.
“There were a lot of telephone calls to (emergency services) informing us that several people had heard a powerful explosion in central parts of Norrköping,” senior police officer Torbjörn Lindqvist said on Sunday morning.
The explosion is reported to have occurred in a building with several shops, as well as apartments on upper floors.
No information has been given in relation whether damage occurred to any property other than the shop where the explosion occurred.
It is currently unclear what exploded or what caused the blast.
The incident is currently being treated as destruction causing public endangerment (allmänfarlig ödeläggelse).
Nobody is currently under suspicion in relation to the explosion.