By The Nation
The explosion occurred at 7.55am on a main road leading to Ban Katupa village in Tambon Bannang Sareng in Muang district.
The three injured rangers were identified as Sathit Rurob, Direk Thongpradub, and Tuansulaiman Tuankortae.
Sathit was severely injured with shrapnel wounds to his stomach while the two others were hit in less critical body areas,
Police said the three rangers were riding on two motorcycles to provide protection for teachers at the Ban Katupa School when the ambush occurred.
Police said insurgents used a mobile phone to detonate the bomb, which was believed to be stuffed with 10 kilogrammes of explosives.