The accident took place last night at Bajrang Ispat located in Tilda Police Station area here when the victims were working close to a blast furnace, Raipur Superintendent of Police Sanjeev Shukla told PTI.
As per preliminary information, when the night shift workers were busy with their task, suddenly a chamber of furnace exploded following which hot liquid fell on them causing burn injuries, he said.
Soon after getting information of the incident, Raipur Collector OP Choudhary and the SP rushed to the spot along with security personnel.
"Two of them were said to be in a serious condition as they have sustained over 80 per cent burns," Shukla added.
Police team and experts have been sent to the spot to ascertain the exact cause of the blast, he said.
A case has been registered in this connection, the SP said adding that further probe was on.