Rescuers in northern India are searching for 24 students washed away in a sudden surge of water released from a dam.

The students were standing on the Beas river's edge yesterday evening taking photographs when they were hit by a wall of water.

The incident happened in the northeast Himalayan state of Himachal Pradesh.

"In the morning five bodies have been found in the Beas river as rescue teams continue to search downstream," senior state government official Pankaj Rai told CNN-IBN news channel.

Soldiers, police and other rescue workers were seen combing the banks of the river, while others in kayaks were paddling slowly downstream, checking around boulders.

Divers have also been called in, an official said.

About 50 engineering students were travelling on buses to the tourist hill station of Manali when they stopped in the Kullu Valley, about 200km from state capital Shimla, officials said.

Teachers and fellow students, from an engineering college in the southern city of Hyderabad, told how they screamed at the group about the torrent of water which appeared without warning.

"I did not walk down to the river but saw the sudden rise of the water and screamed to the students to run but the waters quickly engulfed and swept them away," college staff member A Aditya said CNN-IBN.

"We saw a wall of water hit those who were on the banks. They fell flat and disappeared under the waves," one of the students told the Indian Express newspaper.

The surge of water occurred when a hydroelectric power project opened its floodgates, sending tonnes of water downstream, officials have said.

Anger is mounting about whether any warning was given before the water's release.

Local media reported protests late yesterday by residents on the road above where the accident occurred.