Hyderabad, Feb 23 : Rescue efforts continued on Sunday to save eight persons trapped in an under-construction tunnel in Telangana's Nagarkurnool district, more than 30 hours after a portion of its roof collapsed.

Teams from the National Disaster Response Force (NDRF), the Army, and the Singareni Collieries Company Litd (SCCL) were engaged in intensive efforts to rescue the trapped men.

About 250 personnel of the NDRF, the State Disaster Response Force and 24 personnel each of the Army, the SCCL, and the Hyderabad Disaster Response and Asset Protection Agency (HYDRAA) were participating in the operation.

Officials said rescue workers were 200 metres away from the point where the roof of the tunnel had collapsed on Saturday. The tunnel was flooded with water and silt hampering the rescue efforts.

The rescue workers were making all efforts to reach the tunnel boring machine where the accident happened.

Officials said they had restored electricity supply to the tunnel and were supplying oxygen as part of the efforts to rescue trapped men.

An official said the rescue workers called out trapped men but there was no response.

At least two workers were injured and eight others were trapped when a portion of the tunnel being dug as part of the Srisailam Left Bank Canal (SLBC) collapsed near Domalapenta.

A total of 50 persons were working on the left-side tunnel when the roof collapsed for three meters. The accident occurred at the 14th km point.

While 42 workers came out of the tunnel, the remaining eight were trapped. Those trapped include two engineers and two machine operators.

The NDRF team, which reached up to 11th km in a loco train, found water and mud beyond this point. The rescue workers walked for another 2.5 km to reach closer the spot.

Nagarkurnool district Collector Badavath Santosh said the efforts were being made for dewatering and desilting to move forward.

The rescue teams were also unable to take their heavy equipment near the spot due to water and silt.

Irrigation Minister Uttam Kumar Reddy, who was supervising the rescue operation, said all efforts were being made to pull out the trapped men safely.

The trapped men are from Jharkhand, Uttar Pradesh, Punjab, and Jammu & Kashmir.

Ministers Uttam Kumar Reddy and Jupally Krishna Reddy held a meeting with officials of the NDRF, the Army, and other agencies involved.

Chief Minister A. Revanth Reddy expressed shock over the incident and assured that the government would extend all possible help to the families of the victims.

Prime Minister Narendra Modi on Saturday spoke to Chief Minister Revanth Reddy over the phone, enquired about the incident and assured all support from the Central government.

Top Congress leader Rahul Gandhi also spoke to the Chief Minister on Sunday and enquired about the rescue operations.

The state government had recently resumed the construction work on the tunnel to complete the long-pending project. The construction firm had started work four days ago and on Saturday morning, 50 workers entered the tunnel for the work.

Irrigation Minister Uttam Kumar Reddy said the work was started on the tunnel after a survey by the Geological Survey of India. He told the media that the company which was hired for the work has a good record in digging tunnels.

He said soon after the work began on Saturday morning, water started entering the tunnel and soil caved in. "The workers who came out said they heard an explosion, which could be a geological disturbance,' he said, adding that those who were in front of the boring machine were trapped in the tunnel.

/IANS