Another student was rescued by local fishermen.
A group of seven B Tech students, studying at Gitam Engineering College here, went for an outing at Rushikonda beach on the city's outskirts.
They decided to go for a swim in the sea but were caught in a high tide. One of them was pulled out by local fishermen but others are still missing, they said.
Marine boats along with Naval and Coast Guard helicopters were pressed into service to locate the missing students, police added.