New Delhi, Aug. 13 -- A multi-agency rescue operation is underway in Uttarakhand's Chamoli district after a landslide caused water and debris to enter a tunnel on Thursday, leaving at least six workers trapped, officials said, according to Hindustan Times.

The incident occurred around 7 pm at Tehri Hydro Development Corporation (THDC) Limited's project site in the Pipalkoti area, reported PTI, further citing officials who said that the tunnel is under-construction at a hydroelectric project site.

So far, 16 workers have been safely rescued, according to information released by the state government.

There were 22 workers inside the tunnel, noting that that the sudden influx of debris and water entered it around 1.5 km from its mouth, of...