Six people have received care on site, but no one is seriously injured, the police on their website.
It's some substance that has leaked out, says Martin Johansson at RC Mitt to Aftonbladet.
The alarm came in at 11:30 and the mall has been evacuated of people. The police are also on site in the area.
We're holding the cordons and making sure no new people enter the mall, says Daniel Wikdahl at Stockholm police to the newspaper.
The police have initiated a preliminary investigation into causing bodily harm and creating danger for others.
Just a few days ago, another suspected gas leak occurred at Täby center, where several people were taken to hospital.
