Authorities in Chile are looking at ways to speed up the rescue of 33 miners trapped deep underground for 23 days who officials have said might have to wait three to four months to see the light of day.

Mining Minister Laurence Golborne said rescuers were considering other options, including digging a second escape shaft to rescue the miners, who survived over two weeks on mouthfuls of tinned tuna, cookies and milk.

Officials are due to start digging a shaft about 2 feet (66 cm) in diameter that would take three months to reach the trapped miners. They would be lifted up one by one with a pulley.

But rescuers said they were considering drilling a second shaft closer to the tunnel where the miners are located that would take about 60 days to reach them.

The miners were found alive last Sunday after they tied a note to a drill looking for them 2,300 feet (700 metres) underground, triggering celebrations across Chile and focusing world attention on what would be the toughest mining rescue ever attempted.

In a video released this week, bearded miners, some of them noticeably thin, explained how they organized themselves to survive in a tiny refuge in the bowels of the mountain.

They said they had areas designated to sleep and play dominoes as well as a space for water and items like toothpaste and deodorant.