Phra Sombat Srisuwan, 59, who died on the spot and Phra Thawatchai Chaiman, 23, who was seriously injured, were rushed to Yala Central Hospital, the INN news agency reported.
The shooting came as violence in Thailand's south border provinces escalate since Monday when a group of militants forced their way into a mosque in neighboring Narathiwat province, killing at least 11 prayers, wounding another 12.
Thailand's deep South comprises mainly the three southernmost provinces of Yala, Pattani, Narathiwas, and some parts of Songkla province. Over 3,700 people have been killed by the daily violence attack by the suspected separatists since January 2004.
Defence Minister Prawit Wongsuwan on Thursday said that he will visit the southern border provinces with Suthep Thuagsuban, Deputy Prime Minister for security affairs.
Late Thursday, Prime Minister Abhisit Vejjajiva called a meeting to study an operational plan for the deep South for the next fiscal year, worth 18 billion Baht (US$528 mln).
He instructed officials to hunt down the culprits of the mosque attack but insisted they not set up any scapegoats, which would create more troubles, according to an official at the meeting.
Panitan Wattanayagorn, Deputy Secretary for Mr. Abhisit, said the government would send an additional 1,440 security volunteers to help maintain law and order in Pattani, Yala, Narathiwat and Songkhla districts. The government would allocate a 400 million Baht (US$11.7 mln) budget for the volunteers, he said.
The meeting also approved a proposal by the National Economic and Social Development Board to initiate more than 300 development projects for the region, worth 54 bln Baht (US$1.58 bln), between 2010-2012, he said.