Indian rescuers hope to reach 41 trapped in tunnel on Thursday

Rescuers in India hope to finish drilling through debris on Thursday and free 41 men trapped in a highway tunnel in the Himalayan region after a metal obstacle slowed progress, officials said.

The men began the twelfth day of their ordeal confined in the 4.5-km (3-mile) tunnel in Uttarakhand state since it caved in early on November 12. Authorities have said they are safe, with access to light, oxygen, food, water and medicines.

"Hopefully, by the end of the day, if there are no obstacles, rocks or girders, the operation should be successful," Atul Karwal, head of the National Disaster Response Force, told reporters.

An auger drilling machine has resumed operation, and "that is a very good sign", he said, adding that work to push through more evacuation pipes had also begun.

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Rescuers had expected to drill through the last third of the 60 m (197 ft) of debris blocking the tunnel early on Thursday, but had hit a lattice steel girder arch that took six hours to remove, said Bhaskar Khulbe, a tunnel project official.

Once the drill breaks through, officials said they plan to send rescuers through the evacuation pipe, using stretchers on wheels, to bring out the trapped men.

Ambulances were ready to take the men to a hospital about 30 km (20 miles) away on a route cleared of congestion.

Authorities have not said what caused the tunnel collapse, but the region is prone to landslides, earthquakes and floods. Efforts to bring the men out have been slowed by snags in drilling in the mountainous terrain.

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"We are very close. You all have been very brave. Everyone is praying for you," Pushkar Singh Dhami, the state's chief minister, told Gabbar Singh Negi, one of those trapped, via a wired communication link, in a video clip shared by authorities.

He told another man, Saba Ahmed, that there were just 10 metres (33 ft) left to be covered, adding, "Looks like it won't take too long now."

The collapsed tunnel is on the Char Dham pilgrimage route, one of the most ambitious projects of Prime Minister Narendra Modi's government.

It aims to link four key Hindu pilgrimage sites with 890 km (550 miles) of two-lane road, at a cost of $1.5 billion.

Following the collapse, the National Highways Authority of India will do a safety audit of 29 tunnels it is building, the government has said.