New Delhi/IBNS: The rescue operation to evacuate 41 trapped workers from the Uttarakhand tunnel collapse is expected to be completed by Tuesday night with only 12 metres of rock and debris left to be cleared off, media reports said.

"I am happy to announce we have been able to move forward by another six meters. It is expected that in the next two hours when we prepare for the next phase, we will be able to (finish) remaining work," Bhaskar Khulbe, the Special Officer deputed to the Uttarakhand Tourism Department, told reporters.

Khulbe said about 67 percent of the drilling had been completed.

After being trapped for about 10 days now, the Centre came up with a five-option action plan that involved drilling from three sides to access the trapped workers.  Five different agencies have been tasked with carrying out each operation.

The labourers have been trapped in a 400-metre buffer zone of the unfinished main tunnel since November 12 when a portion of the 4.5-km tunnel on the Brahmakal-Yamunotri National Highway collapsed, trapping 41 workers.

The tunnel - meant to join Silkyara and Dandalgaon in Uttarkashi - is a part of the Char Dham project.

On Monday morning, a wider pipe was installed to deliver a wider variety of food and medicine to the trapped people. Earlier, only dry fruits could be sent in.

The rescue ops involved an international tunneling expert team and a robotics team from defence research organization (DRDO).

Over the last week, several plans to cut through the 40-meter rock wall fell through.

The last rock fall occurred on Friday when attempts were made to use an American Auger drill flown in from Delhi. The drill machine that was being used before that had broken down and work had to be stopped till the new one reached.