The latest victim, Prasarn Chatree, was a defence volunteer.
Maj-Gen Phisit Sitthisarn, head of a special unit in Narathiwat, visited six victims at the hospital and gave them some assistance money.
He said the police are tracking down those responsible and that security is being stepped up to prevent a repeated incident.
Meanwhile, Thanongsak Pongprasert, head of southern train office said it is expected to spend a day Monday to salvage derailed train carriages. He was unable to say when service will resume.
It depends in part on the morale of railway workers and officers, he said.
All southbound trains can run to Yala station, but passengers wanting to travel further South, must transfer to vans or buses.