A motorcycle bomb exploded in front of Rusoh Train Station in the southernmost province of Narathiwat yesterday morning, wounding nine people, including three soldiers.
Two victims - Sergeant Taweewat Onkwanpetch and civilian Mayuni Waeni - were in serious condition.
The vehicle had been stolen from a teacher, Chatsuda Ninsuwan, after she was shot dead on her way home on December 3, 2012, in the same province.
However, it had its licence plate replaced with one from another motorcycle whose owner had reported as missing.
Pol Lieutenant Montri Janmueang of Rusoh Police Station said the blast took place in the parking zone of the train station, opposite Rusoh Market.
"The explosive must have weighed around 10 kilos and was triggered by a radio-communication device," he said.
The three soldiers were returning to their parked pickup truck after shopping at the market, he said.
Six cars and motorcycles suffered minor damage, he said.
Police said that by the time they arrived at the scene, all of the wounded had already been taken to nearby hospitals.
The other victims were two rangers, Witoon Majangneed and Prasittichai Permpoon, and six civilians including a girl who remains hospitalised.
Two received just minor injuries. Following treatment, they were allowed to go home.
Former Narathiwat MP Jeh-aming Tohtayong said the militants could still stage violent attacks in the deep South partly because security officials could not set up full-scale checkpoints in deference to local people who need to live a normal life.
"It is now necessary that besides using military measures, authorities also actively engage local people in ensuring safety," he said.
While authorities need to enforce laws to protect the peace, they also need to respect human rights and refrain from acting at the spur of the moment, he said.
The latest violent incident would hopefully not derail the peace dialogue that Thailand was preparing to resume with groups behind the unrest in the deep South, he added.