Thirty-three people were also stuck in Malana II power project in Manikaran area of Kullu district.
Deputy Commissioner Kullu, Torul S Raveesh, said 29 out of the 33 have been rescued.
A wall and way to a tunnel was damaged due to rains and water entered the barrage but the teams of the NDRF and home guard managed to rescue 29 people, while four persons are still in the power house.
The relatives of the missing people are campaigning at the spot and the Army, National Disaster Response Force (NDRF), Indo-Tibetan Border Police, State Disaster Response Force, police and home guards are involved in the rescue operations and the help of drones is being taken to locate the missing persons, officials added.
The maximum damage was caused in Samej area of Rampur subdivision of Shimla district as a cloudburst near Shrikhand Mahadev on Wednesday night triggered flash floods in Sarpara, Ganvi and Kurban nallahs.
As a result, the water in Samej Khud in Shimla district's Rampur rose, leaving two people dead and about 30 missing, Shimla Superintendent of Police Sanjeev Kumar Gandhi had told PTI.
«We have to search about a 100-km area, some of which is inaccessible and drones are being used to locate the missing people, » Gandhi had told PTI on Thursday.
Nali Ram, a senior citizen who along with his family members managed to escape the flash floods, said, «I heard the sound of gushing waters and came out of my house only to find the area around flooded».
The swelling of Samej Khud resulted in havoc in Shimla and Kullu