The incident occurred due to "signal overshooting" as both the trains started moving in the same direction though signal was given for one to depart Jharsuguda station, about 110 k from here, GRP DSP at Jharsuguda, M K Mahato said.
While one Bikash (24) of Sambalpur was admitted to a hospital at Jharsuguda, three others were discharged after first-aid.
Samaleswari Express left for its destination after a halt for about six hours, Mahato said.