The fire at a Woodstock superette has been isolated to two 48kg gas bottles on the premises.

The City’s Fire and Rescue inspectors found that while the canisters were still intact, the gas had been used to fuel a two-plate cooker.

It’s believed that a leak could have developed due to the increased pressure of the larger canisters.

The leaking gas had then created a “blanket” that crept along the floor until the shop had become completely saturated, including soaking the clothes of the two victims as they stood behind a counter close to the entrance of the shop.

The inspectors say that the fire was started from the induction motors used in the refrigerators.

Officials say an initial blast went off, and then a fire broke out, followed by several secondary explosions.

Two people, including the shop owner, sustained serious burn wounds, and were rushed to Groote Schuur Hospital for treatment.