Two Class 1 students were locked in an iron chest by their teacher for being inattentive in the class at Adisaptagram village in West Bengal's Hooghly district on Friday.
The teacher, Chandan Ghosh, then forgot all about the kids and left the school.
The students, Sujan and Sadhan Das, reports said, were dragged by Ghosh to the principal's room and locked the iron chest used to store note-books.
When the school was about to close for the day, some employees heard the sobbing of the children. They then broke the box open to find two teary-eyed boys cowering with fear.
The boys were given first aid and are fine now.
A senior police official said if the children were not rescued in time, they would have suffocated to death.
The teacher is absconding.