Thailand's military said 17 insurgents were killed early Wednesday during an attack on a military base in the country's south.
Thai military spokesman Pramote Promin said at least 60 men, armed with military-grade weapons, stormed the base and were repelled.
He said the military had received a tip and was ready for the attack.
Promin also said that during the intense fighting some Thai soldiers were injured.
It was not immediately clear who was behind the attack or why it occurred.
Thailand's population is overwhelmingly Buddhist, but three southern provinces near the border with Malaysia are majority Muslim. An insurgency calling for more autonomy has simmered in those areas since 2004.