At least six back-to-back cracker blasts ripped through railway tracks near Hussainabad, Hyderabad and Noushero Feroz districts on early Sunday, suspending the rail service.
Portions of railway tracks have been destroyed in the explosions, however no loss of life or injuries have been reported.
Police and Railways officials converged to the explosion sites and examined the magnitude of damages.
Officials said that a minimum of five hours are required to complete repair work so as to restore railway service.
It may be mentioned here that a couple of hours earlier, two identical blasts of crackers destroyed some portion of railway tracks near Nawabshah, suspending the train service in the area.
Security officials investigating the blasts said that they had found the pamphlets of Sindhu Desh Liberation Army near the explosion site.
According to officials, a security plan to protect the tracks has been put in place with the assistance of the Sindh police, and round-the-clock patrols are underway to check any sabotage activity.