Published: Nov 22, 2010 5:12 PM EST
Updated: Nov 22, 2010 2:11 PM EST

GREYMOUTH, New Zealand (AP) - Police and mine rescue crews in New Zealand have acknowledged for the first time that the 29 miners trapped underground since Friday may not have survived the blast.

Police superintendent Gary Knowles said Monday that rescuers were keeping an open mind.

Knowles added: "But we are planning for all outcomes, and as part of this process we're planning for the possible loss of life as a result of what's occurred underground."

Toxic gases have prevented rescuers from entering the mine and there has been no contact with the missing men.

Drilling of a small shaft into the mine to test dangerous gas levels was expected to be completed later Monday, and experts were preparing a military robot to enter the mine and take pictures.

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