Operations to rescue 40 labourers trapped in a tunnel have been hampered after a landslide at the site and technical problems with a drilling machine being used to create an escape passage, officials said.
The labourers are safe, and oxygen, electricity, medicines, food items and water are being constantly supplied to them through pipes, they said.
Meanwhile, workers, family members and others held a protest outside the under-construction tunnel over the delay in rescuing trapped labourers.
The protestors vented their anger over the absence of an alternative plan when the machines deployed for drilling the rubble to prepare an escape passage for trapped labourers did not work on Tuesday evening.
A portion of the under-construction tunnel, which is part of the ambitious Chardham All Weather Road project, collapsed on Sunday.
The 30-metre collapsed section is 270 metres from the mouth of the tunnel from the Silkyara side.
On Tuesday night, rubble from the landslide fell on the collapsed part of the tunnel, hampering operations as well as injuring two rescue workers.
They are being treated at a makeshift hospital, the officials said.
A new platform is being built inside the tunnel for another drilling machine, which is on the way, an official at the police control room set up near the site, Sanjit Uniyal, said on Wednesday.
Some more equipment is being brought from Delhi by air to aid rescue efforts, according to officials of the state and national disaster response forces.
They added that the drilling machine at the site is facing some technical problems.
The Tuesday landslide hampered efforts to insert steel pipes through the tunnel's debris to create the passage.
Talks have been held with the Indian Air Force and soon bigger machines will be sent to the spot from Delhi so that the stranded workers can be taken out of the tunnel at the earliest, Uttarakhand's Director General of Police Ashok Kumar told PTI in Dehradun.
Nearly 40 workers have been trapped behind debris for over 72 hours.
According to a list of the trapped workers issued by the emergency operation centre, 15 are from Jharkhand, eight from Uttar Pradesh, five from Odisha, four from Bihar, three from West Bengal, two each from Uttarakhand and Assam, and one from Himachal Pradesh.