A fire caused major damage at a local department store Lee Mart Super Ka Song in Trang town early Friday.
No one was injured but the entire three-storey building may be a write-off, with estimated damages of 100 million baht.
The fire was reported to police at around 4am Friday, 10 hours after a bomb in Trang’s Walking Street market killed one person.
Police were investigating whether the Lee Mart fire was caused by a bomb, but said it might also be arson or even an electrical short-circuit.
About 50 police officers and soldiers, firefighter teams and more than 20 water trucks rushed to the scene in tambon Tubtiang in Muang district, Trang municipality.
Nguad Hengchuan, 65, a security guard at the department store said about 3am, the smell of smoke awoke him. He said he heard "an explosion and loud noise" and saw flames from the floor above him.
He ran to safety and called for help. There was no one else in the store, which was locked from the outside after hours.
Chantip Rangsiprakan, vice mayor of Trang Municipality, said it was difficult to control the fire as firemen could not contact the owner to open the store. It took more than three hours to control the fire.
Lee Mart, originally called Diamond Department Store, opened about 30 years ago.