They were studying in Class X in Mary Immaculate School in Lakkasandra Extension near Wilson Garden here.
Girl students alleged that the principal of the school and a teacher chastised both the girls for playing Holi inside the school premises on Monday.
Police rushed to the scene and found a suicide note.
The incident came to light at around 1 pm on Tuesday when the gardener at the park noticed school bags, slippers and other belongings of the girls.
Police is investigating. The principal and school teacher are being questioned.