The incident occurred at around 9 P.M. At Unit No.7 of the National Thermal Power Corporation (NTPC) plant when labourers and engineers were at work there, a senior police official told PTI.
The cause behind the blast is yet to be ascertained, he said, adding that a probe has been opened into the incident.
Six workers and two engineers received burn injuries in the mishap, he said.
The victims were rushed to a local hospital from where they have been shifted to Apollo Hospital in Bilaspur district, he added.