A rupture in the water supply pipeline had led to severe flooding of the Kopili hydropower plant at Umrangsho in Assam's Dima Hasao district on Monday morning.
"The NDRF team have arrived here but failed to carry out search and rescue operations as the water level in the project site is very high. They are trying to reduce the water level," Assam State Disaster Management Authority's District Project Officer, Riki Phukan said.
NEEPCO authorities also said that they are trying to reduce the water level.
With more than 24 hours already over, the hope of the four missing officials of the project remaining alive have seemingly dimmed.
The locals, however, blamed the NEEPCO authorities for the tragedy and said that the tragedy took place as requirement for maintenance of the power plant was ignored by the authority.
NEEPCO officials said that the four officials including three staffers identified as Robert Baite, Prem Pal Balmiki, and Joy Sing Timung were working at the power house when the inundation took place.
The water supply tunnel carries about 12,000 litres of water per second and water fountain rose up to hundreds of feet after the rupture.
The spillover water had also flooded some parts of the Umrangsho town on Monday.
( With inputs from IANS )