"The rescue and recovery team are working hard on ensuring the operation is expedited, but with the utmost measures being taken to ensure the safety of the teams," the zinc unit of India's Vedanta said.

Eight workers were rescued after the accident, and one died.

The mine shutdown has helped push prices for zinc, a metal used to galvanize steel, to an 18-month high.

At full production capacity in phase 1, Gamsberg will produce 250,000 tonnes a year of zinc in concentrate, according to Vedanta's website.

(Reporting by Helen Reid, editing by Louise Heavens)