The police said Subham Pankaj, Aditya Raj, Nitish Kumar and Chandranath Roy drowned at about 2 pm when Subham went to take bath in the water.
Seeing him to drown, Aditya, Nitish and Chandranath jumped into the water to rescue him but they too drowned, the police said.
Local fishermen recovered the bodies after an hour. All the drowned students came to study here from Jharkhand and Bihar.
They along with seven other classmates of fourth year B Tech Mechanical stream went to the barrage this noon for sightseeing, officials said.