The New Zealand miners trapped underground after an explosion may be dead warned New Zealand Prime Minister John Key.
29 men have been buried in the mine since Friday and no contact has been made with them. The men, aged 17 to 62, are believed to be about 1.2 miles down the tunnel.
Key said: “We hope and pray that the missing men are alive and well.
“But given we have not had contact with the men for nearly four days, the situation remains grave. Although we must stay optimistic, police are now planning for the possible loss of life.
“Our thoughts go out to all those who are suffering unbearable anxiety and distress as they wait for information about their loved-ones.
“We share their frustration. We too are impatient to see a rescue team sent in but we also realise the toxic and explosive gases could cause more casualties.”
Key said police were planning for possible deaths as the mine is still swirling with toxic gases and is too dangerous to send in rescue.
“Toxicity is still too unstable to send rescue teams in,” said police superintendent Gary Knowles
The rescue effort ran into trouble earlier when a remote-controlled robot sent into the mine broke down, leaving officials needing more advanced equipment to be flown in.
The explosion, in Pike River Mine, is thought to have been caused by a build-up of methane gas. The presence of methane and other gases are delaying a rescue over fears they could still explode.
While authorities wait for more advanced equipment, rescuers are using a diamond-tipped drill to bore through layers of hard rock to get closer to tunnels where some of the miners are thought to be trapped.
Cameras and listening equipment will be lowered into the borehole in an attempt to pick up any signs of life from trapped miners.
Optimism about finding the miners alive is wearing then. “With the passing of time, we are preparing for all options,” said Supt Knowles.
Related: Pike River mine disaster update