"We have detained three senior company officials after complaints that the incident took place due to their negligence," District Superintendent of Police M.R. Mohanty told IANS.
The explosion occurred around 10 a.m. in a blast furnace at the steel plant of Bhushan Steel Ltd at Narendrapur village, 150 km from state capital Bhubaneswar.
All the victims were contractual labourers. Although firefighters brought the fire under control, the exact number of casualties and injured was still unknown, he said.
District Collector Rupa Roshan Sahu said the incident occurred while the furnace was being commissioned, and investigation was on to find out if the company had permission to do that.
A witness said more people could be buried under the debris.
The state government has ordered a probe into the explosion.
Hundreds of workers and local residents blocked a local road and staged a demonstration for several hours demanding action against plant officials.
The steel plant, commissioned in 2006, manufactures pig iron, billets, slabs and hot-rolled steel coil. It has an annual output of about 3.1 million tonnes. The company had announced to increase its capacity to six million tonnes by the end of this year.
A company official said the blast furnace was handled by foreign experts and such incidents were not uncommon.
However, an official of the state pollution control board said the company had been accused of violating pollution norms several times in the past.
The board had also served a closure notice to its captive power plant in August.
--IANS (Posted on 13-11-2013)