The rescue operations to pull out the eight persons trapped inside the partially collapsed SLBC tunnel here for a week saw a breakthrough on Saturday with the whereabouts of four of them being located, though a Telangana minister put the chances of their survival at “one per cent.” State Excise Minister Jupally Krishna Rao, who attended a meeting with officials involved in the rescue operation along with Irrigation Minister N Uttam Kumar Reddy, said there was lot of progress during the last couple of days.

“In my view, the whereabouts of four persons have been located through radar,” he told reporters at the tunnel and expressed hope they would be extricated by Sunday evening.

Asked about the condition of the four whose whereabouts have been found, the minister recalled he had said on the first day itself that the chances of survival of the trapped persons are remote.

“I had said the chances (of survival) are very, very remote. I am not talking about it but waiting in view of one per cent possibility (for survival),” he said.

Krishna Rao added desilting was being carried out manually where the whereabouts of four persons has been identified which is expected to be completed by Sunday evening.

Scientists from the National Geophysical Research Institute (NGRI) used Ground Penetrating Radar (GPR) and detected some “anomalies” inside the tunnel, providing a crucial lead in the operation.

The other four appear to have been stuck beneath the Tunnel Boring Machine (TBM), the minister said. It may take some time to get a breakthrough about them, he said.

The 450 ft tall TBM was being cut, he said.

The personnel of about 11 agencies, including Army, NDRF, rat miners, are involved in the operation.

Referring to the criticism of opposition parties that the operation is getting delayed, Krishna Rao said those involved in the endeavour are experts but the rescue work is complex in view of the conditions, including slush, inside the tunnel.

The rescue personnel should not be put at risk, he said.

The minister also said dewatering, repairing the damaged conveyor belt and other aspects of rescue work is going simultaneously.

Krishna Rao also said the families of those trapped in the tunnel were waiting as the operation was underway.

Eight persons–engineers and labourers have been trapped under the collapsed roof of the Srisailam Left Bank Canal (SLBC) tunnel since February 22 and the rescue operations are on in full swing to pull them out to safety .

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)