Also, police today registered a case against the four boys, all 10th standard students of the school at Chintamani, following a complaint by the boy's parents.
They said the boy in his purported suicide note mentioned that four of his classmates, had teased his manner of walking and described his behaviour as feminine, which had upset him.
Unable to bear the taunts, the boy took the extreme step, by hanging himself from a ceiling fan yesterday at his house in Nerunjalakudi near Lalgudi, 15km from Tiruchirappalli.
The boy's mother filed a complaint with the local police.
Superintendent of Police SC Kalyan rushed to the spot and assured that suitable action would be taken against the boy's classmates following which the protesters dispersed.
Police said a case has been registered against the four boys.
The boy's parents were also unhappy about the alleged indifferent attitude of the school teachers on the boy's complaint against the bullying.