One of the probe committees formed over Sirajganj train accident has suggested the accident was caused by a problem in the rail tracks, as found during their primary investigation.
"In the primary investigation, no problems were found in the signals. It seems that the accident occurred due to a problem in the rail tracks," said Pakshi Western Rail Division Divisional Traffic Officer (DTO) Md Abdullah Al Mamun on Friday.
"Four employees of the Local Public Works Department (PWD), also railway employees, have been brought to Sirajganj Government Railway Police (GRP) station for interrogation," the DTO added.
Md Abdullah Al Mamun was made the head of the five-member probe committee formed by Pakshi Divisional Railway Manager (DRM) office on Thursday.
Three other probe committees have been formed by the Ministry of Railways, Sirajganj district administration and Rajshahi Western Rail Division to investigate into the accident.
On Thursday, the engine and seven bogies of Rangpur Express derailed after the train, bound for Rangpur, left the Ullapara rail station. The engine along with four bogies caught fire.
Around 25 people were injured in the incident.
After the accident, rail links between Dhaka and the northern districts remained cut for nearly seven hours, collapsing the schedule of trains of that route.