Some of the 40 workers trapped inside a collapsed tunnel in India have fallen sick as efforts to rescue them entered the fourth day.

Rescue teams on Wednesday said that they had sent medicine to the trapped employees, some of whom had fallen sick inside the tunnel. Two of the workers were also reported injured due to falling debris.

Mounting fears over a delay in the trapped workers' rescue  have angered the families of the workers who gathered outside the tunnel.

District official Abhishek Ruhela said some workers had said they were suffering from fever, body aches, and nervousness.

Along with food, water and oxygen, medicines are also now being sent to the workers through pipes that were set up earlier. 

Delay in rescue of the trapped workers

Three days have passed since the road tunnel which was being constructed on a national highway in India's Uttarakhand state, collapsed.

Technical faults and falling debris have impeded the rescue efforts. The rescue operation was delayed because of a technical fault with the drilling machine, an official told the Associated Press news agency.

About 200 personnel using drilling equipment and excavators were also unable to reach the trapped workers on Wednesday too as heavy rocks were blocking the way.

"A heavy machine is being brought in from New Delhi to insert an evacuation pipe as the current one is being blocked by boulders," a senior official told Reuters news agency.

mfi/rc (AP, AFP, Reuters)