Miners told that rescue operation could take four months

A group of workers trapped in a collapsed mine have been told they may be stuck underground for months before rescuers can free them.

Officials on Wednesday said it could take up to four months before the 33 men can be freed, saying until then they will get oxygen, food, water and medical supplies.

The news was delivered as the government prepared a special programme to help the miners cope mentally and physically with their prolonged captivity.

Chilean engineers said they needed at least 120 days using a hydraulic bore to dig a narrow escape shaft measuring just 66 centimetres in diameter, or roughly the size of a mountain bicycle wheel, to get the men out.

Rescuers on Tuesday began sending down emergency food, water and oxygen supplies to the miners trapped alive after the gold and copper mine collapsed on August 5.

The mine runs like a corkscrew for more than seven kilometres under a barren mountain in northern Chile's Atacama Desert.