Train services on the northern route have returned to normal after being disrupted by the derailment of an express train to Chiang Mai on Wednesday morning, the State Railway of Thailand (SRT) said on Thursday afternoon.
All trains from Bangkok to the northern city of Chiang Mai were now running to schedule after the track was given safety clearance, SRT spokeswoman Nuananong Wongchan said.
Repair crews had put the derailed cars back on the track, towed them away and fixed the damage to the lines, following the accident about 3.45am on Wednesday between Pak Pan and Kaeng Luang stations in Phrae province, she said.
SRT governor Prapat Chongsanguan was at the site this afternoon looking into the cause of the derailment, which injured 30 passengers, most of them foreigners.
The Nakhon Ping overnight express service from Bangkok to Chiang Mai is very popular with tourists.
Seven of the 10 coaches carrying 290 passengers left the track.
An initial investigation pointed to deteriorated track conditions as the cause of the accident, which occurred as the train slowed to the required 40 kilometres per hour to take a curve in the hilly terrain of the northern province, Ms Nuananong said.