They were among six BPP officers on patrol travelling in a pickup truck and on a motorcycle in Sungai Kolok district. Investigators found the remains of an improvised explosive device estimated to have weighed 10 kilograms at the scene of blast. The four injured police were taken to Sungai Kolok Hospital while their vehicles were badly damaged in the explosion.

The attack was believed to be the work of insurgents targeting local security forces and public officials, the police said.