The bodies have been identified as that of Dip Sarkar, Dayal Sheikh and Jit Das.
The other student, Abinash Das, is yet to be traced.
The locals noticed the schoolbags of the students on the bank of the Brahmaputra at 2 pm on Sunday.
The locals said all the four students went to the Brahmaputra for swimming after returning from the tuition class.
The personnel of the State Disaster Response Force (SDRF) and the National Disaster Response Force (NDRF) launched a search operation in the river Brahmaputra.
Sources said the school students made a reel video on a mobile smartphone before jumping into the Brahmaputra for swimming.
The smartphone was later recovered on the bank of the mighty river.
According to sources, all were Class 10 students of Vidya Mandir school.
They were aged 15 years.
The schoolbags and slippers of the students were recovered earlier.