Pol Maj Jakkapong Lueng'on of Kathu Police said police were investigating the cause of the transformer explosion, which set fire to the top storey of the restaurant.
The owner of the restaurant, Mayawee Saejew, 37, said there was a lot of heavy rain and wind last night and she heard a loud bang sound. She panicked and ran outside to see what had happened. By this time the second storey was on fire.
Six fire trucks were sent to the restaurant, which is located on Soi Paisanee Gao, Taweewong Rd, in Patong. By this time there were plenty of shocked tourists around, who watched as firefighters took around 30 minutes to extinguish the blaze.
An investigation has been started into details of the cause of the fire.