But rescuers later said survey equipment showed the first drill had "drifted" about 26 metres from its target.
 
Rescuers next plan to insert a lining into the new drill hole, a process that will take hours but would protect a camera and allow it to send back good images, officials said.
 
"Survivable space"
 
Richard Stickler, the US Mine Safety and Health Administration chief, has said that there is drinkable water and a "survivable space" where the second 20cm drill pierced the mine ceiling.
 
It is expected to take four to five days to dig an opening large enough to pull the miners out.
 
Meanwhile, the larger drill hole would be used to provide food, water and air until they are rescued.
 
Officials have said the men could potentially hold out for weeks in an underground chamber if they survived the initial collapse.