A strong “gas-like” odor forced an area of the international terminal to be temporarily evacuated Tuesday afternoon at Hartsfield-Jackson International Airport.

Employees in the customs area smelled the odor around 2:30 p.m., an airport spokesman said. About 100 passengers were affected before the fire department re-opened the area.

The odor may have been fumes from a propane-powered tug, which pull aircraft around, which may have gotten into the HVAC system, the airport spokesman said. The cause of the smell was not determined.