LUCKNOW, India (AP) — Some of the 40 construction workers trapped in a collapsed road tunnel for a fourth day were sick as falling debris and technical glitches delayed the work to free them, officials in northern India said Wednesday.

Wide pipes are set to be drilled through excavated rubble to create a passage to free the workers trapped since Sunday when a portion of the under-construction road collapsed in mountainous Uttarakhand state.

That is testing the patience of the relatives and friends of the trapped workers gathering outside the tunnel who are growing frustrated and angry with reports that some workers were falling sick.

Magistrate Abhishek Ruhela said some workers have sent messages that they are suffering from fever, body aches, and nervousness. Medicine has been sent through pipes that were set up earlier to get water and food to the workers.

“Essential eatables such as gram and almonds are being sent through the same channels,” Ruhela said.

Two of the workers also were reported to have minor injuries from the falling debris.

Most of the workers are migrant laborers from across India.

About 200 disaster relief personnel are using drilling equipment and excavators in the rescue operation. Steel pipes 2.5-foot (0.76 meter) wide, which arrived at the site Tuesday, will be pushed through an opening of excavated debris with the help of hydraulic jacks to safely pull out the stranded workers.

Gaurav Singh, a state government official, said the rescue operation was delayed because of a technical fault in the drilling machine, but a new machine has been installed.

Falling debris also had delayed the start of the drilling on Tuesday. "These are challenges in such rescue operations, but we will overcome them,” Ranjit Sinha, a disaster management official, said.

A landslide Sunday caused a portion of the 4.5-kilometer (2.7-mile) tunnel to collapse about 200 meters (500 feet) from the entrance. It is a hilly tract of land, prone to landslide and subsidence.

Uttarakhand is a mountainous state dotted with Hindu temples that attract many pilgrims and tourists and construction of highways and buildings has been constant to accommodate the influx. The tunnel is part of the busy Chardham all-weather road, a flagship federal project connecting various Hindu pilgrimage sites.