The identities of the deceased could not be known immediately.
The injured were admitted to Gazipur Shahid Tajuddin Ahmed Medical College Hospital for treatment.
Officer-in-Charge of Sadar Police Station confirmed the matter.
Witnesses said a Kolkata-bound Maitree Express train knocked the truck as it suddenly broke down on the rail track, leaving one dead on the spot and three others injured. Another died on way to hospital.
Locals rescued two injured and sent them to the hospital after the accident, the OC said.