The effort to free two Australian gold miners trapped underground for 11 days entered its most delicate — and dangerous — phase on Saturday, as rescuers completed work using a giant drill and prepared to cut the last few meters of an escape tunnel by hand.

Matthew Gill, manager of the Beaconsfield Gold Mine said rescuers were now within 3 meters (10 feet) of Brant Webb, 37, and Todd Russell, 34, and had finished boring through solid rock with a giant drilling machine.

Countrywatch:Australia

Once the drill had been removed, hand tools would be used to chip away the remaining rock and dirt between rescuers and to the men, in an attempt to avoid causing a cave-in.

Gill said it would take several hours to remove the boring machine and "get the final and most difficult stage underway."

"It is not known how long this will take and the rescue effort must be done safely," he said. "The rescue tunnel will be inspected and supported and air vents and lighting will be installed in preparation for the final stage. We are still unable to put a time on when rescuers will break through to Todd and Russell."

Officials have indicated it is likely the men will have to spend another night underground.