The improvised bomb was hidden in a pickup truck and went off late Friday night in the basement of the Central Festival mall on Samui Island in Surat Thani province, after a fashion show, the island's disaster prevention and mitigation chief Poonsak Sophonpathumrak told The Associated Press.
He said authorities believed the vehicle was stolen from one of the three southernmost Thai provinces plagued by Islamic insurgency. More than 5,000 people have been killed in the three southern provinces since 2004.
Poonsak said the bomb destroyed most of the pickup truck and damaged a few other vehicles that were parked nearby at the mall, which is located a few hundred feet from the popular Chaweng beach.
"The authorities are still investigating the scene to find out more details before linking it to any insurgency groups," he said.