A concrete block is carried into the tunnel where rescue operations are underway in Uttarakhand, India. Reuters

Indian rescue teams digging by hand are now within five metres of 41 men who have been trapped in a collapsed road tunnel for over two weeks, officials said Tuesday, saying a breakthrough was expected "soon."

After repeated setbacks in the operation, military engineers and skilled miners are working by hand in a painstaking dig through rock and rubble towards the men using a so-called "rat-hole" mining technique to clear the final stretch.

Some five metres (16 feet) of rubble remain, chief minister of Uttarakhand state Pushkar Singh Dhami told reporters at the site as rescue efforts entered their 17th day.

"The escape passage has been prepared up to 52 metres inside the tunnel, and the passage will break through at 57 metres," Dhami said Tuesday morning.

"The rescue operation is expected to be completed soon," he added, without giving a specific timeframe, raising hopes the end was in sight for the marathon operation.

However, previous hopes of reaching the men have been dashed by falling debris and the breakdown of multiple drilling machines.

The government has repeatedly warned that timelines are subject to "technical glitches, the challenging Himalayan terrain, and unforeseen emergencies".

The 41 construction workers have been trapped since November 12 in a tunnel being constructed between the remote towns of Silkyara and Dandalgaon in the Himalayan state of Uttarakhand.

Agence France-Presse