Rescuers attempting to reach workers who have been trapped for nearly a week in a collapsed highway tunnel in the Indian Himalayas are striving to resume operations after encountering a setback.

The main digging machine encountered difficulties, prompting efforts to replace it on Saturday.

The disaster management office has updated the number of people trapped in the tunnel in Uttarakhand state to 41, up from 40 since Sunday morning. All individuals are reported to be safe, according to authorities cited by Reuters.

On Friday, the augur machine, which was drilling through the debris, broke down. A new machine has been brought in from the central Indian state of Madhya Pradesh and has arrived at the site, as confirmed by Anshu Malik Halko, the director at the state-run National Highways and Infrastructure Development Corporation (NHIDC).

The cause of the 4.5-km (3-mile) tunnel collapse has not been disclosed by authorities, although the region is known for its susceptibility to landslides, earthquakes, and floods.

During the overnight shift at the time of the collapse, approximately fifty to sixty workers were in the tunnel, and those near the exit managed to escape onto the national highway, which forms part of the Char Dham Hindu pilgrimage route.

Operations were halted on Friday after a "large-scale cracking sound" was heard while rescue workers were attempting to restart the drilling machine, according to an NHIDC report.

On Saturday, nearly 100 tunnel workers gathered at the site, expressing their demand for quicker progress in reaching and freeing those who are trapped. Vishnu Sahu, a laborer leading the protest, alleged that the rescue team is not providing transparent information about the pace of the rescue operation.