The attack occurred on the Cho Airong-Bango Kubo road at Ban Aiyapae of Cho Airong district about 9.40am, aid Pol Col Suchart Sa-Ey, chief of the Cho Airong police station.
Lt Prathit Kaewphai, chief of Ranger Company 4808, told police that he and two rangers were travelling in a pickup truck leading six other rangers on three motorcycles when a home-made bomb was detonated.
Ranger Songsak Phumphet and a passing villager, Yeh Sulong, 71, were wounded by the blast. They were taken to Cho Airong hospital.
Lt Prathit said he believed the bombers were targeting him. But the bomb exploded shortly after his pickup passed by and the explosion hurt Ranger Songsak, who was on a motorcycle behind.