Two teenagers, aged 18 and 19, have been arrested and bailed pending further enquiries after the Embleton Court shops caught fire in the early hours of November 1.
No one was seriously injured in the attack, although a woman was taken to hospital after being rescued from a flat above the parade. Two takeaway outlets and a hairdressers were among the other businesses gutted in the blaze.
A spokeswoman for Sainsbury's, which owns the Bells chain, said: "We are keen to get things up and running as soon as possible, especially as we know this is an important parade for the local community.
"Staff who worked at the store are now working at other stores nearby. Levels of stock at these outlets have been increased to meet the extra demand."