The Asecs mall in Jönköping, southern Sweden – home to some six dozen stores such as H&M, Ikea and Systembolaget – was evacuated at around noon after several people took ill.
Police and emergency services were called to a hamburger restaurant in the building after several people started coughing and one person fainted, reported Swedish media.
In total, 19 people were taken to hospital and 40 were cared for at the scene, but their injuries were minor and according to emergency services the gas was not toxic.
“Emergency officers believe it was carbon dioxide. It is a harmless gas, but it displaces the oxygen. That can lead to breathing difficulties and that is what makes you faint,” Sofia Merkert, information officer at the emergency services in Jönköping, told the TT newswire.
Half of the shopping centre was temporarily cordoned off. It is believed the gas leak came from a soft drink machine at the restaurant, and police suspected no crime or foul play on Friday.