"Four lives were lost due to collapse of a rock formation on the hillside," NMDC, India's largest state-owned iron ore miner, said in a statement.

Two contractual workmen who sustained injuries are being treated at NMDC Hospital and are now out of harm's way, the company said, adding that the rock collapse was "unpredictable" and it was investigating.

"The workers were employees of Larsen and Toubro (L&T)", Gaurav Rai, a top Dantewada police officer, told Reuters.

NMDC did not specify if the workers were L&T employees, and L&T did not immediately reply to Reuters' request for comment.

(Reporting by Neha Arora and Manvi Pant; Editing by YP Rajesh and Varun H K)