Two monks were killed while two others seriously injured after militants armed with war weapons opened fires on them at their temple in Narathiwat's Sungai Padi district on Friday night.
It appeared to be the first time that a Buddhist temple became the target of the attack.
Witnesses said a group of about ten men riding on motorcycles raided Rattananuparb Temple in tambon Tohdeng in the province at about 8.30pm.
They said some monks were fired at close range. One of the slain monks were Phra Kru Prachotirattananurak, chief monk of the district.
One of the monks was announced dead at a hospital nearby.
The ambush sent people living near the temple run for cover while some hid in their houses.
When security forces arrived at the scene, the attackers already fled the scene.