17-year-old Md Israfil and 15-year-old Robeya Khatun were married about eight months ago
Railway authorities said the incident took place near the Shahjibazar Rail Station.
Sayestaganj Railway Junction's Station Master Md Moazzul Haq said two carriages of train carrying cement went off-track.
"The derailed carriages have been removed and the tracks are being repaired. Train services may resume around 5pm," he said.