A caller to Triple Zero reported the smell of gas coming from a commercial building on La Trobe Street just before 11am.
Police helped evacuate about 100 people from the building while firefighters investigated the source of the odour.
The incident was deemed until control just before 1pm, Fire Rescue Victoria said.
About 21 firefighters helped isolate the gas supply to make the scene safe.
Ambulance Victoria assessed a number of patients on scene, but no emergency treatment or transport was required.
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