Hope faded for 28 men trapped underground in a New Zealand coal mine for six days as rescuers managed to restart on Wednesday an army robot looking for signs of life in an access tunnel.
The robot, equipped with four cameras, broke down 500 metres into the tunnel at the Pike River mine on Tuesday after reportedly being struck by a waterfall.
Soldiers managed to restart it on Wednesday morning and parked it nearly halfway up the 2.2-kilometre tunnel, sending in a second robot to follow it, Radio New Zealand reported.
Meanwhile, a 162-metre deep borehole intended to transport a camera and listening device had still not been able to penetrate unexpectedly hard rock.
Nothing has been heard from the trapped men since a gas explosion at the mine Friday. Police chief Gary Knowles said it remained too dangerous to allow a search and rescue party of 65 miners to proceed into the mind.
Knowles admitted that the situation was increasingly bleak for the men, but told Radio New Zealand that authorities were still looking at all the options of a rescue operation.
Relatives of the missing men, aged 17 to 62, are becoming increasingly angry and frustrated at the failure to mount a rescue, but with air samples showing that a fire is still smouldering underground, Knowles said the risk of another explosion was too great to risk lives of the rescuers.
Yellow ribbons have been tied on lamp posts and power poles in Greymouth, the mining region's main town, and churches are holding nightly prayer vigil services.