RESCUE teams trying to reach 41 construction workers trapped in a collapsed tunnel in northern India for nearly two weeks stopped drilling again today after their boring machine hit a new metal obstruction in rock debris.

Disaster management officer Devendra Patwal said it might take the rescuers several hours to cut the metal object and resume the final phase of digging at the accident site in Uttarakhand state.

Mr Patwal said the machine had been stopped after it had drilled about 6.5 feet of the last stretch of 40 feet of rock debris that would open a way out for the trapped workers.

The work was previously paused on Thursday after the platform of the drilling machine became unstable while boring through rock debris, halting the final phase of digging at the accident site in Uttarakhand state for about 20 hours, state government spokesman Kirti Panwar said.

He could not say how long it would take to complete the drilling and to bring the construction workers out.

They have been trapped since November 12, when a landslide caused part of the tunnel they were building to collapse.

Before the work resumed, rescuers manually dug through debris to remove pieces of metal and prevent further damage, Mr Panwar said.

The mountainous terrain in the area has proved a challenge for the drilling machine, which broke down last weekend as rescue teams attempted to dig horizontally toward the trapped workers. The machine’s high-intensity vibrations also caused more debris to fall.

The drilling also had to stop on Wednesday after the boring machine hit a metal girder, damaging its blades.

The trapped workers, mostly migrant labourers from other parts of India, are being supplied with food, water and oxygen through pipes.