Sama-ae Doloh, a sub-district chief in Pattani province, was driving his pickup truck to work when at least three men in another truck blocked an intersection and opened fire, Police Capt. Theera Iedchata said.
Sama-ae's truck was riddled with bullets, and he was taken to a hospital where he was pronounced dead. Police gathered bullet casings at the crime scene from AK-47 and M-16 assault rifles but have not identified the assailants.
Pattani is one of three southern provinces where Muslim separatists have been fighting a long-running insurgency against the Buddhist-dominated government. About 7,000 people have been killed since it escalated dramatically in 2004.
Police did not know the motives for targeting the official or the store.