Rescuers are only metres away from reaching nine workers trapped underground in a Peruvian mine, but rescue efforts have been delayed by a small cave-in.
Jorge Merino, the mining and energy minister, said the workers were expected to be freed early on Wednesday.
He cautioned against a hurried rescue operation, saying there was a risk of further cave-ins and collapses inside the Cabeza de Negro copper mine, 325km south of the capital, Lima.
The miners have been trapped for six days in a tunnel 250m underground in a horizontal tunnel after a shaft collapsed after an explosion set by the workers.
President Ollanta Humala visited the mine late on Tuesday. "There have been some setbacks caused by the structure of a rock," Humala said. "We have to wait a few hours more."
Efforts to rescue the men have ramped up in recent days, with people arriving from nearby mines to help efforts to hold up the delicate tunnel that rescuers are digging.
Oxygen, soup, water and medicine have been sent through the miners through a hose that also lets them talk with people outside.
Some of the workers reported stomach infections, but they were otherwise in good health. They range in age from 23 to 59 years.
Cabeza de Negro is an unlicensed mine that was abandoned more than two decades ago by its owners, but continues to be exploited.
With international market prices for metals high, informal "wildcat" mining has been on the rise in recent years in Peru, one of the largest producers of silver, copper and gold.
The trapped miners' fate recalled a similar case in Chile that made world headlines.
In August 2010, 33 miners were trapped in a cave-in in the San Jose gold and copper mine in northern Chile. After 69 days and a spectacular rescue operation with the world watching, they were brought out safely.