According to Deputy Superintendent of Police Ran Vijay Singh, two charred bodies of the technicians beyond recognition were recovered from the debris.
Two other technicians, Nand Lal and Kshati Prasad, have been hospitalised with severe burn injuries in Safdarjung hospital in Delhi.
The area has been cordoned-off as police are suspecting more causalities, he said, adding that identities of the deceased were not established yet.
The rescue and search operation was on till the last report came in.