The alarms went off at Portfield Retail Park, near Chichester, and emergency services have evacuated Currys, John Lewis and Marks and Spencer as a precaution.
A spokesperson for West Sussex Fire and Rescue said officers and one crew from Chichester Fire Station are on the scene, carrying out an investigation.
"Other premises at the site are still operating as usual, but would urge people to avoid the area at this time if their journey is not essential,” they added.
5. Suspected gas leak at West Sussex Retail Park
John Lewis was also evacuated. Other shops are operating as normal, but shoppers are urged to avoid the area, if possible. Photo: Eddie Mitchell
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