A top National Disaster Management Authority member on Tuesday said the entire evacuation process to pull out trapped labourers from a Uttarkashi tunnel might take three to four hours.

Lieutenant General (Retd.) Syed Ata Hasnain addressed a press conference when he said: "It is estimated that it will take 3-5 minutes to evacuate each of the 41 trapped persons."

"The entire evacuation is expected to take 3-4 hours," he said.

Uttarakhand Chief Minister Pushkar Singh Dhami on Tuesday confirmed that the pipe-laying work to reach the trapped 41 labourers inside the Silkyara tunnel in Uttarakhand has been completed.

Interestingly, the Rat-hole mining method, a primitive coal extraction procedure, which is banned in India for being unsafe, was used to rescue the labourers after imported machines broke down and halted the process of evacuation.

Rat-hole mining experts began their work on Monday after a 25-tonne auger machine failed during the last phase of the operation.

The labourers have been confined in the tunnels for the past 17 days.

According to reports, the labourers will be taken for an initial health checkup in a temporary medical facility established inside the tunnel.

They are expected to be taken to a hospital in Uttarkashi after being rescued from the tunnel.