Raipur, Sep 23 - At least 15 workers were killed and some 50 were trapped under debris when a chimney of an under-construction power plant of Bharat Aluminium Company Ltd (Balco) collapsed in Chhattisgarh's Korba town Wednesday afternoon, police said.

The state government has ordered a judicial inquiry into the incident that took place when about 100 workers and engineers were engaged in the construction work at Balco Nagar area, some 250 km north of state capital Raipur.

'It's a massive accident that has claimed at least 15 lives. We have launched a rescue and relief operation to save about 50 workers and engineers trapped under the collapsed chimney's debris,' district Superintendent of Police Ratanlal Dangi told IANS on phone.

The state government instructed the district collector and superintendent of police to

register a first information report (FIR) against the Balco management for allegedly overlooking security aspects and announced a judicial probe into the accident.

The state also announced compensation of Rs.100,000 to the family of each of the deceased.