Police said Atikom Tiwong, 34, a teacher at Ban Prachan School in Yarang district was riding his motorcycle from the school to his home when he was assaulted, shot in the head and body by at least three assailants.
Police found empty AK47 and M16 assault rifle cartridges at the scene of the attack.
Mr Atikom, a native of Chiang Mai province, had been teaching in Pattani for two years.
In an incident in neighbouring Narathiwat province, police reported a bomb explosion on Sakor-Waeng Road in Sungai Padi district.
Police found the remains of a home-made bomb contained in a 15kg fire extinguisher with a mobile phone attached. No one was killed or wounded in the incident.