COPIAPO, Chile — The crew drilling one of three shafts attempting to reach 33 miners trapped deep underground in northern Chile is making fast progress, officials said, and could reach the miners by early next week.

The T-130 drill, part of an effort dubbed "Plan B," burrowed 53 meters (173 feet) in 16 hours and is a mere 100 meters from a chamber the trapped miners can access, said Andre Sougarret, the engineer in charge of rescue operations.

The news raised hopes among relatives camped on the surface that the trapped miners could be out by early next week.

Sougarret, however, was cautious about setting a time frame because work was entering a delicate phase.

Drilling operations have been paused until midnight, and will resume at a slower pace because it will be boring down a mere meter (yard) away from a separate corridor inside the mine. If the corridor is breached it could create problems for the rescue operation, Sougarret said.

"We are decreasing the drilling speed so that we get by the corridor carefully," said Sougarret.

"Once we have reached 535 meters (1,748 feet) of depth, we can resume the rhythm that we have had up to now," he told reporters outside the mine.

The miners, who have been trapped underground for two months, will be extracted one by one in a custom-built cage that has an outer diameter of 23 inches (58 centimeters).

They will be wearing special sunglasses to protect their eyes when they emerge into the daylight, after more than two months in near-darkness.

"The benefit (of the glasses) is that they filter out the sunlight. They do not cause any problems," but do give eyes more time to adjust to light, said Alejandro Pino, regional manager of the Chilean Safety Association at the San Jose mine.

The special glasses were donated by a US company, and have a market price of 450 dollars a pair.