Hyderabad, Feb 22 : Rescue efforts were on to save eight persons trapped in an under-construction tunnel after a portion of its roof collapsed in Telangana's Nagarkurnool district on Saturday.

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.

Police, fire services personnel, and officials of the Irrigation Department rushed to the spot and launched rescue operations.

Teams of the State Disaster Response Force (SDRF) and National Disaster Response Force (NDRF) joined the rescue operation in the evening.

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

State Ministers Uttam Kumar Reddy and Jupally Krishna Reddy rushed to the spot at the direction of Chief Minister A. Revanth Reddy and were monitoring the rescue operations.

The Chief Minister expressed shock over the incident. He asked all departments concerned to actively participate in the rescue operation and directed officials to ensure the best treatment for the injured.

He assured that the government would extend all possible help to the families of the victims.

The state government had recently resumed the construction work on the tunnel to complete the 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.

"The government is making all possible efforts to rescue the trapped persons. We are getting the best tunnel experts in the country to oversee the rescue effort," he said. He admitted that there would be challenges as the accident happened 14 km inside the tunnel.

He said Chief Secretary Santhi Kumari spoke to officials who were engaged in the rescue operation after a similar incident in Uttarakhand recently.

Meanwhile, Prime Minister Narendra Modi spoke to Chief Minister Revanth Reddy over the phone and enquired about the incident.

The Prime Minister informed him that an NDRF team would be deployed immediately for rescue operations and assured all support from the Central government.

The Chief Minister briefed the Prime Minister about the incident and told him that a rescue operation was on to save the trapped men.

/IANS