41 workers trapped in Uttarakhand's Silkyara tunnel for the last 11 days are likely to be rescued in the next few hours or by tomorrow, National Disaster Management Authority (NDMA) member Lt Gen (retd) Syed Ata Hasnain said on Thursday evening.

The drilling work to pull out 41 trapped workers encountered obstacles, which resulted in a temporary stoppage of rescue efforts.

"I expect that in the next few hours or by tomorrow, we will be successful in this operation," Hasnain said in a media briefing.

The NDMA member also said that the horizontal drilling to rescue workers may face 3-4 more hurdles.

He also noted that it would not be fair to speculate on the timeline for rescue operations as it is just like fighting a war.

Hasnain further said that 41 ambulances, one each for trapped workers, are in place at the tunnel site, and also facilities are in place to airlift workers in serious condition.

The men have been trapped for the past 11 days after a portion of the under-construction tunnel on the Uttarakhand Char Dham route collapsed, cutting off its exit.

Rescue operations to evacuate the workers resumed on Thursday morning after an overnight hurdle delayed the drilling by several hours.

According to the government's latest media bulletin, NHIDCL has resumed horizontal boring from the Silkyara end to rescue workers using an Augur boring machine.

A metallic object (Lattice girder rib) was encountered in the front of the pipe and the pipe could not be inserted further. Cutting of Metallic object (Lattice Girder rib) using Gas cutters has been completed at 0230 hrs.

The trenchless team entered into pipe manually twice to confirm the clearance of the rescue pipe.

The media bulletin said the pushing of the 9th pipe started at 1310 hrs, and the pipe reached to additional 1.8 metres.

Besides, the fabrication of a protective canopy for the drilling machine is underway.

The government has undertaken a five-option action plan to rescue the workers and five agencies namely Oil and Natural Gas Corporation, Sutluj Jal Vidyut Nigam, Rail Vikas Nigam, National Highways and Infrastructure Development Corporation, and Tehri Hydro Development Corporation have been assigned specific responsibilities, working collaboratively with occasional task adjustments for operational efficiency.

THDC has initiated the construction of a rescue tunnel from the Barkot end, with four blasts already completed, resulting in a 9.10-metre drift. Efforts are being made to carry out three blasts per day.

Equipment for micro tunnelling required for horizontal drilling to rescue labourers has reached the site. Platform likely to be completed by November 24, 2023. Equipment is to be set up by November 25, 2023.

Work is underway to create a drift inside the tunnel, with a safe channel established from 180 metres to 150 metres.

The Army is mobilising box culverts for this purpose. Fabrication of frames has started.

BRO has completed the construction of an approach road for vertical drilling by SJVNL and RVNL. It is also building an approach road for ONGC with geological surveys conducted by the oil company. It has also made an access road of 300 metres.

The area of entrapment, measuring 8.5 metres in height and 2 kilometres in length, is the built-up portion of the tunnel, offering safety to the labourers with available electricity and water supply.

Silkyara tunnel, about 30 km from the district headquarters of Uttarkashi and a seven-hour drive from the Uttarakhand capital Dehradun, is part of the ambitious Char Dham all-weather road project of the central government.

Except for the headline, this story has not been edited by The Telegraph Online staff and has been published from a syndicated feed.