Several small explosions have hit the southern border province of Narathiwat ahead of celebrations of its 100th anniversary.
The homemade bombs exploded late on Friday night, damaging 15 electricity poles and toppling four of them in Sungai Kolok district.
Some of the improvised explosive devices were attached to electricity poles along two separate roads - Sungai Kolok to Tak Bai and Sungai Kolok to Sungai Padi.
Local officials from the Provincial Electricity Authority urgently repaired the damaged power poles so that electricity supply could be resumed late in the evening yesterday.
Bomb disposal experts examining the scene had to detonate some unexploded bombs at a rubber plantation not far from where they were planted.
Police suspected that the well-coordinated attack was the work of separatist insurgents, according to Police Colonel Kongath Suwannakham, superintendent of the Sungai Kolok district's police station.
He said investigators were convinced the attack was carried out by the same group of perpetrators who were responsible for explosions at eight locations in Sungai Kolok in the night of July 10. That attack left three people dead and several others injured.
There were at least two separate incidents yesterday morning, according to Colonel Banphot Poonpien, of the Army's Internal Security Operations Command.
Local police sources say that the bombs targeted electricity poles to disrupt a Muay Thai boxing match, which had been arranged for the centennial celebrations. The boxing match was scheduled for yesterday in Narathiwat's Sungai Kolok district.
Officials don't see any link between the bombings and the blast in Bangkok on Monday, which killed 20 and injured more than 100.
Some police sources said that the attack might be linked to some senior members of the separatist Patani United Liberation Organisation who are living in Malaysia.