So far seven bodies have been fished out but others remained untraceable, according to Superintendent of Police (SP) Hari Narayanchari Mishra.
"A total of 12 persons, belonging to three families of Hanuman Tal area, went to the Bagdari waterfall picnic spot and crossed a rivulet in which water level was shallow," he told reporters.
However, when they were crossing the rivulet while returning from the spot, the water level rose suddenly and all of them were swept away, the SP said.
"So far, seven bodies have been recovered and search is on to trace the remaining people," he said.
District Collector, Vivek Porwal has announced an ex-gratia of Rs 1 lakh each to the kin of those killed in the mishap.
The victims were not identified yet, the SP added.