The three labourers, trapped for more than 120 hours inside an under-construction tunnel which collapsed on Saturday night, are expected to be rescued within 24 hours as the rescue operations have reached its final stage.

As much as 30 meters of horizontal insertion within the collpased tunnel has been done and 10-15 meters additional drilling needs to be done. It is expected that they would be rescued in the next 24 hours, said Manasi Sahay Thakur, Deputy Commissioner.

Massive rescue operations is underway to retrieve the employees trapped inside tunnel No 4 of Kiratpur-Nerchowk four-lane project near Bilaspur in Himachal Pradesh on September 12.

"The boring from the vertical end was made to facilitate supply of food and water to the trapped, the labourers were given water after the contact was established with them," she said, adding that the administration, on advice of doctors, was providing food, dry fruits, glucose, adequate water to the trapped workers.

Two of the three trapped labourers were confirmed to be alive on Wednesday as the rescue teams established contact through digital camera and microphone after hours of digging. However, there has been no communication established with the third employee trapped in the debris, and his condition remains unknown. Efforts were on to find him, Thakur said.

Meanwhile, Chief Minister Virbhadra Singh rushed to Tihra on Thursday to monitor the rescue operations.

To assess the present situation, Chief Minister went inside the tunnel and took stock of the situation. He expressed satisfaction over the rescue operations and consoled the family members of the trapped persons.

The Chief Minister separately talked to each of the family members and assured them of all possible help from the government. He also urged them to keep patience as it would take some time to bring them out.