Northern Gas Networks (NGN) engineers are responding to reports of a gas leak outside the shop in New Street.
Mark Taylor, NGN network officer, said: “Staff have been evacuated from the building as a precaution and our teams are on-site working hard to establish and repair the cause of the gas escape.
“Safety is our priority and engineers will remain on-site throughout the day while we work to makes repairs as quickly as possible.”
Anyone that smells gas or suspects carbon monoxide should call the National Gas Emergency Service immediately on 0800 111 999, NGN said.
The line is in operation 24-hours a day, seven days a week.