
Two of the power relay lines were blown up in the morning and the other two in the afternoon in spite of step up of troops to Joh I Rong district, traditionally a highly contested area between the insurgents and the security forces.
Police found pieces of wristwatches at the scenes of the attacks and believe that they formed part of the trigger mechanisms.
Police said the five bombs were similar in size and composition. They believed the same group carried out the attacks.
Authorities heading to investigate the three locations were stalled by more acts of sabotage, as insurgents spiked the roads with nails and blocked traffic with logs.
Firefights and roadside bombings targeting the security forces have occurred regularly in this highly volatile area.
In a separate incident, a 15-year-old youth was shot dead in Narathiwat by a gunman riding pillion on a motorbike. The motorbike approached the victim from behind and the gunman opened fire with a 9mm pistol.
Wae-hama Tuankama was believed to have been singled out as an informant for the police in Joh I Rong and the Sungai Padi district. He was employed at a karaoke bar in Muang district.
The Nation