Three private hospitals, along with large areas of Alipore and Ekbalpore, went without power for hours on Friday afternoon, following a fault in an underground cable.

CESC blamed the fault on the micro-tunnelling work of Reliance Communication.

A Reliance Communication official said supply to BM Birla Heart Research Centre tripped shortly after micro-tunnelling work started.

“CESC said the tripping might have been caused by our tunnelling work. We stopped work in compliance with the power utility’s order,” said a Reliance official.

“We had a talk with Reliance officials. They have been told to work in close coordination with us,” said a CESC official.

Calcutta Medical Research Institute (CMRI) and BM Birla went without power from noon to 4pm. “Surgeries were not hit but tests like CT Scan angiography were,” said Rupak Barua, the chief operating officer of CMRI.

At Woodlands Hospital, power went off twice. “Services were not affected as we have a generator back-up,” a hospital official said.

Power minister Mrinal Banerjee said he had asked CESC to improve the transmission and distribution network.

“We were forced to resort to power cuts from 4.10pm on Friday as the West Bengal State Transmission Company Limited restricted its supply to our grid,” said a CESC official.