The Uttarakit Road market in Krabi City was destroyed by fire at 2am this morning.
Firefighters in four engines took about half an hour to control the fire. A house was also damaged.
More than 20 gas cylinders have been taken away for testing and the roads are blocked off.
Forensic investigators are trying to establish the cause.
Capt Teerayut Poerat of Krabi police, who was on scene during the blaze, said: “While I was patrolling near Krabi bus station, I saw smoke and fire. Locals were helping to put out the fire before they called firefighters.”