Union minister V K Singh on Thursday said all efforts are being made for an early and safe evacuation of 40 labourers trapped inside the Silkyara tunnel in this Uttarakhand district for more than four days, but the rescue operation could take two or three more days.

"It (evacuation) can happen even sooner than that but in circumstances like this, we should keep an outer limit of two-three days so that we can deal with an obstacle if it comes," Singh told reporters after visiting the tunnel.

"Our priority is that they stay safe. Our priority is that they are evacuated at the earliest. All efforts are being made for that," the Union minister of state for road transport and highways said after reviewing the rescue operation.

He said he has spoken to the trapped labourers. "They are safe and their morale is high," Singh added.

"The workers are trapped between the collapsed part of the tunnel and a two-km-long area where there is a constant supply of oxygen, electricity, food and water," he said.

Speaking on the disaster-vulnerability of the area where a cave-in occurred on Sunday, Singh said, "According to data, it was stable for four-and-a-half years. But for some reason, the cave-in occurred." He said these mountains are young and fragile.

"All this will be examined once the rescue operation is over," he added.

Asked whether there will be a high-level inquiry into the reasons that led to the collapse, Singh said it could be considered once the rescue operation is over.

"We would look at that when our minds are settled. Our focus now is to evacuate our people safely as early as possible," he said.

An alternative strategy is also in place and if one machine stops for some reason, the other will start working, the Union minister added.

"We will not let the operation stop. Rest assured," he said.

Singh said the central and state governments and all the agencies engaged in the rescue operation are working in close coordination with each other for the safe evacuation of the labourers, and Prime Minister Narendra is being regularly updated about the developments.

Constant consultation is also being held with tunnelling technology experts from a global organisation who possess the highest level of expertise in rescue operations of a specific nature, he said.

Consultations are also being held with mining and railway experts so that the most suitable methods are adopted for the safe evacuation of the labourers, the Union minister added.

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