New Delhi, July 24 -- Thai authorities said Thursday they are searching for the people responsible for an attack in the country's troubled deep south region that killed five soldiers and injured several civilians.

About 10 attackers opened fire and threw pipe bombs at soldiers at a security check point near a residential area in Narathiwat province Wednesday evening before fleeing, according to the regional Internal Security Operations Command. It said six civilians were injured during the attack, including a 10-year-old boy who remains hospitalized in stable condition.

Photos released by authorities showed a group identified as the attackers, dressed in black clothing and hats and riding on the back of a black pickup truck. Security of...