Amrit Das and Debapriyo Das were both students of Class XI of Fanindra Deb High School.
Amrit's body was recovered from the river in school dress. Debopriyo was yet to be traced, police said.
They said it appeared that the two boys had gone to the river bank on a bicycle from school and had ventured into the water.
The cycle and their school bags were recovered from Teesta spur II, police said.
Local boys who saw the two being swept away, were assisting the police in rescue operations.