The attack occurred about 6.30am when a team of rangers from Rangers Company 3314 were on foot patrol to provide security for teachers along Thanto - Puyut road in tambon Thanto, about 2km fro Highway 410 (Yala - Betong).
A group of militants hiding on both sides of the road detonated a land mine and opened fire at the rangers in an ambush. The soldiers returned fire and the militants withdrew after a 15-minute clash.
One ranger, Donchai Saeng-aree, was killed by the bomb. Another ranger, Jakri Khammee, was slightly injured.
The incident took place ahead of the planned visit to Yala on Monday morning by Gen Udomdet Seetabutr, the deputy army chief and secretary-general of the National Council for Peace and Order (NCPO), and officials of the National Security Council (NSC).