Four engineering students drowned in the Krishna river in Andhra Pradesh on Saturday.
The incident is said to have occurred at Ibrahimpatnam's Pavitra Sangamam, a suburb of Hyderabad in Ranga Reddy district, 35 kilometres from Hyderabad.
They were students of MIC Engineering College in Kanchikacharla district.
Police said the students of a private college came to Pavitra Sangamam, the confluence point of the Godavari and Krishna, along with another classmate, for a visit.
As one of them tried to get down into the river, he accidentally slipped and was washed away. Three others tried to rescue him but the force of the water pulled them also into the river, a police official said.
National Disaster Response Force (NDRF) personnel have launched operations to trace them.
A police officer said that about 100 people were taking part in the rescue operations. Rescue teams of the SDRF, fire service and other departments were also called in.
Krishna district in charge collector Vijaya Krishnan has rushed to the spot to oversee rescue operations, the police added.
Chief Minister N Chandrababu Naidu expressed grief over the incident.