The attack tore apart cement sleepers and tracks in about a 20-metre radius but no one was injured as there were no trains in the vicinity at the time.
Manop Muenpreecha, Tanyongmas station chief, said the attack affected six trains running through Sungai Kolok station.
Workers have not yet gone to the scene to fix the damaged tracks because they have to wait for soldiers to clear the area for their safety.
Manop said the repair would take about two days.
Meanwhile, violence in the deep southern province of Yala continued unabated with two people killed in a bomb attack in Bannang Sata district as the Muslim holy month of Ramadan draws to an end.
Many people had expected the situation during Ramadan to be more peaceful but such hopes were disappointed by the killing of Mahamayuding Puteh and Assuwan Yusoh and other attacks in the restive region.
Both men, who were active in fighting militants in the area, were riding a motorcycle on their way home from a mosque when the explosive detonated.
The attack took place at about 1am yesterday, with bomb squads having to wait until 9am before inspecting the scene near a bridge in the district.
Police found a damaged motorcycle as well as debris from a fire extinguisher and electronic circuits.
They estimated that the |explosive used in the attack weighed about 10 kilograms.
Police said the victims were linked to Pol General Sompien Eksomya, a former Bannang Sata police chief killed in an attack in 2010.
Meanwhile, a bomb squad destroyed an explosive using a high-pressure water gun that was found beside an electricity pole near Yaha Crown Prince Hospital in Yala’s Yaha district.
The one-month Ramadan |festival is expected to end |tomorrow, pending an announcement by the Sheikhul Islam Office.
In Narathiwat province, a bomb hidden near a road was triggered in Yi-ngor district on Saturday as a team of 15 soldiers passed on the way back to their base.
The explosion wounded two soldiers who were travelling in the back of the vehicle.