Three villagers were killed when gunmen opened fire at them as they were leaving a mosque in Pattani's Panare district on Wednesday night.
Pol Lt-Col Manit Panthong, chief of the Pattani forensic police, said 16 spent AK47 cartridge shells were recovered from in front of the mosque at Ban Na Phrao in tambon Panare.
The attack occurred about 9.40pm.
A pick-up truck parked near the mosque and two nearby houseswere also hit by AK47 bullets, he said.
Police were investigating, but initially blamed Muslim militants.