"It was a major incident. Nine people have died so far," Vijay Mairal, the spokesperson of the Bhilai Steel Plant, told IANS. He added that the death toll could go up.

The Bhilai plant, located 30 km west of the state capital Raipur in Durg district, is India's sole producer and supplier of rails for Indian Railways.

Shares of SAIL fell as much as over 4 per cent on Tuesday after news of blast was flashed by news channels.

"In an unfortunate incident on Tuesday at around 10.30 a.m., there was a fire in the gas pipeline of Bhilai Steel Plant's Coke Oven Battery Complex No 11 during a scheduled maintenance job," the company said in a statement.

It said: "The fire has been controlled. So far, nine persons have lost their lives and 14 are undergoing medical treatment. All resources have been mobilized to provide adequate care to the injured."

The injured were rushed to the Bhilai plant's Sector 9 hospital.

The disaster triggered anger against alleged poor safety arrangements by the plant management despite repeated requests by trade unions at the sprawling complex.

The production at the plant was halted on Tuesday as hundreds of workers trooped out in panic after the incident and refused to resume work.