Pol Sub-Lt Somchoke Mankong, duty officer at Yaring police station, said the attack occurred about 9.30am on Highway No 32 (Pattani-Narathiwat) at Ban Thung Kha, tambon Piyamumang, Yaring district.
According to witnesses, eight rangers were patrolling on foot along the highway when gunmen hiding in a roadside palm plantation fired at them with war weapons. The rangers fired back and the attackers retreated after a 10 minute gun battle.
Ranger Sugornai Yusoh, 21, was shot in his left leg and taken to Pattani hospital.
Police blamed separatist militants.