Police said the attack occurred on Highway 401 (Yala-Pattani) at Ban Bannang Kuwae in tambon Bannang Sata of Bannang Sata.
Dauramae Darasae, 54, and his wife Ar-esoh Hengdada, 49, were driving home in a pickup truck with a nephew, 12, and a niece who was two years and eight months old when they were attacked by a gunman riding pillion on a motorbike.
Dauramae was shot and lost control of the truck, causing it to ram into a kilometre marker on the roadside. The gunman then approached them and fired several shots into the vehicle, killing the couple and their niece. The young boy was injured and taken to Bannang Sata hospital.
Police collected eight spent cartridges from a 9mm handgun at the scene.
Police are investigating the motive for the attack, but suspect it was the work of members of the Runda Kumpulan Kecil (RKK) separatist group who are active in Yala. Sources were quoted as saying the group had accused defence volunteer Abdulhakim, Dauramae’s son, of threatening and bullying local villagers and vowed revenge against him.