"Production of hot metal in Bhilai Steel Plant was affected after fire broke out in the cable tunnel of its Power and Blowing Station (P and BS) late last (Sunday) night," a statement said.
"No person has sustained any burn injuries. A few people were affected by smoke and were immediately discharged after giving first aid. Only one person is under observation," the statement added.
The P and BS supplies compressed air to the steel plant's blast furnaces which produce hot metal. The fire had been brought under control when last report came in at noon.
The Bhilai Steel Plant is located in Durg district of Chhattisgarh state, about 30 km west of capital Raipur.
An official at the SAIL unit said the production was hit severely and it may take several days for the plant to resume normal production. The plant produces 17,000 tonnes of hot metal daily on an average.
The Bhilai plant had seen a record production in fiscal year 2008-09 as it produced 5.4 million tonnes of hot metal, 5.2 million tonnes of crude steel and 4.5 million tonnes of saleable steel.