'I have already ordered a judicial probe that will comprehensively investigate the chimney crash issue,' he told reporters near the site.

Pointing towards the workers, he said: 'I can assure you strict action will be taken against those found responsible for overlooking safety aspects.'

Dozens of workers hired by Gannon Dunkerley and Company Ltd (GDCL) for construction of the 275-metre chimney for the 1,200 MW coal-fired power plant and several others who were at the canteen and store rooms close to the crashed chimney are missing and are believed to be under the debris, state Minister Brijmohan Agrawal told IANS.

Agrawal, who is supervising the rescue operation, said substandard construction material used could be the reason for the chimney collapse.

The Balco management and GDCL officials avoided visiting the crash site throughout Thursday fearing attacks by workers.

At the site, dozens of workers and women were beating their chests and crying, fearing the worst for their kin and colleagues.

'It came crashing like thunder. For a moment, I thought it was the sound of thunder as it was raining heavily at the time. But I soon realised that it was the chimney that was coming down,' Dayaram, a 28-year-old worker, told IANS at the Balco hospital where he was recovering from his injuries.

He was near the crash site when the accident occurred around 4 p.m. Wednesday.

Both his legs were fractured as he was hit by parts of the chimney.

'I was in a group of eight colleagues. We began running to avoid the crumbling structure. I can't believe I am alive,' said the contract worker from Bihar's Vaishali district.