The release of water from the Chungthang dam led to a sudden increase in water levels up to 15-20 feet high downstream, defence spokesperson Lt Col Mahendra Rawat said.
North Sikkim was cut off again due to a heavy landslide on the road linking worst-hit Mangan barely hours after it was cleared earlier on Tuesday. Official sources said the landslide occurred 2 km ahead of Dikchu barely hours after troops and relief teams had opened the road to Mangan, the epicentre of Sunday evening's 6.8 temblor that rocked Sikkim and the northeastern, eastern and northern state.