At least 10 workers were killed when an under construction dam near Rongli in East Sikkim district collapsed on Thursday night, police said on Friday.
The toll, however, could mount as the exact number of labourers at the site during the time of accident was not known, Superintendent of Police M.S. Tuli said.
Though police had initially put the number of deaths at 12, Tuli later clarified that they had so far confirmed only 10 deaths.
The under-construction dam collapsed at around 9 pm on Thursday night, washing away over a dozen labourers engaged in the contruction, he said.
The dam was being built between Lamaten and Rolleck areas for storage of water of the Rangpo River for power generation at the 99 MW Chujachen hydel project.
An FIR has been registered under Section 304 (A) of the IPC against the private developer and another company for the accident, the SP said.
However, no arrest has been made as yet, he said.
Meanwhile, efforts are on to retrieve bodies of the missing labourers, but since a large quantity of water had seeped into the tunnel, the rescue personnel were finding it difficult to trace the bodies, police sources said.