No one has claimed responsibility, but there is only one group in Thailand that opens fire on Thai soldiers. Thai Jihad Update. "Bomb near mosque kills soldier in Thai south," from [1] Reuters, January 29 (thanks to Twostellas):

PATTANI, Thailand (Reuters) - A bomb killed a soldier in the compound of a mosque in southern Thailand on Friday and two other soldiers were wounded in a gun battle that subsequently broke out with suspected insurgents, police said.

A small homemade explosive was detonated in the mosque compound in Pattani province as the three soldiers stood guard while colleagues went inside the mosque to pray, Police Major General Pichet Pitisethapan told Reuters.

A group of assailants then opened fire, leading to a five-minute gun battle that wounded the two soldiers, he said....