In a statement, police determined that the Storo Storsenter centre was now safe after the perpetrator, who appeared to have acted alone, fired at least one shot inside.
Norwegian police said on Monday that a shopping centre in the capital Oslo was safe to reopen for business after a gunman opened fire inside.
No one was immediately reported injured and the suspect was taken into custody.
In a statement, police determined that the Storo Storsenter centre was now safe after the perpetrator, who appeared to have acted alone, fired at least one shot inside.
Incident commander Tomm Berger told public broadcaster NRK that the man had a knife and a bat and fired a shotgun round into the ceiling.
There was no evidence to suggest he had tried to hurt anyone, he said.
Following the incident the building was evacuated before police determined it was safe to reopen just before 11:30 am.
Storo Storsenter is the largest shopping centre in Oslo with around 140 stores and cafes.