The bag was discovered shortly after 8am and the terminal was evacuated.
“We have started investigating a bag, which was spotted by security guards. It wasn’t immediately possible to confirm that the item was not dangerous, so the investigation continues,” Stockholm police spokesperson Towe Hägg told the TT newswire on Monday morning.
“No one will get into Terminal 5 and the ones who are there are being made to leave,” said Hägg.
But shortly after 11am, police confirmed that the bag was not dangerous, after inspecting its contents.
It was not immediately known why the bag was initially perceived as suspicious.
Terminal 5 has been home to all of Arlanda’s flights during the coronavirus pandemic. No flights were able to take off during the incident.