File picture.

New Delhi - Six workers died in a poisonous gas leak at a Brazilian-owned steel plant in India's southern state of Andhra Pradesh on Thursday, police said.

The accident occurred following maintenance work at the unit in the Anantapuramu district.

"While testing, they used a gas in the furnace that had large components of carbon monoxide that the workers inhaled and died," senior police official GVG Ashok Kumar said by phone.

Two workers died on the scene, while four others died at the hospital, he said.

Police denied local media reports that said more workers were in serious condition after the accident.

The steel mill belongs to Brazilian firm Gerdau, a leading producer of long steel products in the American subcontinent.

Repeated phone calls to company officials went unanswered. State authorities have ordered a probe into the accident, police said.

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