Snr Sgt Maj Wiroj Noothong of the Phuket City Police was called to the scene, on Thepkrasattri Rd northbound, at about midday.
Police together with Koh Kaew Municipality firefighters and Kusoldharm rescue workers arrived at the scene to find local people together trying to extinguish the fire.
Flames had engulfed a cooking station and had set alight cables on a power pole at the front of the restaurant. The flames had spread to the top of the power pole, where more cables were starting to catch alight.
Firefighters called the Phuket Electricity Authority (PEA) to have power supply to the pole shut off so they could extinguish the fire.
The firefighters took about 30 minutes to completely douse the flames.
Piyarat Wannaphet, 30, told police that she was cooking when she saw sparks coming from the power pole, so she quickly moved the gas cylinder, which was placed close to the pole.
However, the valve on the gas cylinder was still open, and when she moved the cylinder the hose disconnected from the cooker she was using.
Gas coming out of the cylinder caught alight, setting the cooking station on fire, she said.
The ensuing flames also set the cables on the power pole alight, she explained.
Ms Piyarat suffered minor burns to her arms, and was taken to Vachira Phuket Hospital for treatment.
Snr Sgt Maj Wiroj noted that from an initial inspection of the scene officers estimated the damage caused by the fire to be about B50,000.
Police will have forensic officers investigate the scene, he added.