Hundreds of shoppers and staff have evacuated The Shires shopping Centre in Trowbridge after a suspect bag was found.
The suspicious item was found at about 1.30pm after which police sealed off the area.
Police and the fire service are now awaiting the arrival of bomb disposal experts from the Ministry of Defence.
A police spokesperson said: "We are currently working with the owners of The Shires and have had to evacuate the area to ensure public safety.
"Our message to the public is stay away from the shopping centre until further notice.
"We apologise for this inconvenience but public safety is our main priority."
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