SONGKHLA: Three railway workers were killed and four of their colleagues injured when another bomb exploded yesterday at the site of Saturday's railway bombing in Sadao district, officials said.
Local police were informed of the latest blast at 6.24am.
It happened at the site where a freight train was derailed in the first attack, in tambon Tha Pho between Khlong Ngae and Padang Besar train stations.
The blast killed three workers and slightly injured four of their colleagues while they were salvaging the damaged freight train.
The bombers targeted a temporary salvage command post about 400 metres from Saturday's blast site.
The dead were identified as Yingsak Chumtree, Phumphan Phetsuka, and Nawarit Suwanchatree from the State Railway of Thailand (SRT)'s branch in Hat Yai district.
The injured were Noppadol Panma, Deeden Khongsom, Chatchai Nitchalanoont and Theerapong Nukhong.
SRT governor Nirut Maneephan said the SRT was extremely saddened at the loss of the three staff members and was ready to provide assistance and compensation to their family members as quickly as possible.
Mr Nirut said the SRT was coordinating with security forces to probe the circumstances surrounding the incident and step up safety measures for its staff and passengers.
The explosion came as the seven workers collected equipment, including gas cylinders, for the salvage operation.
The previous blast badly damaged 20 freight train cars loaded with rubber sheets en route to Malaysia.
A number of powerful explosions have shaken the deep South in recent weeks, including one at some police flats in Narathiwat on Nov 22 and attacks at petrol stations in Pattani on Nov 16.