Nusrat, who suffered 80 percent burns, was put on life support at 11:30 am on Saturday, said the victim’s brother Mahmudul Hasan Noman.
Earlier, Nusrat had accused Sonagazi Islamia Senior Fazil Madrasa Principal Sirajuddoula of sexually harassing her.
The principal was arrested on March 17 and subsequently suspended. A number of students pressed for his release while another group demanded his punishment.
She went to Sonagazi Islamia Senior Fazil Madrasa centre around 9:30 am on Saturday to attend Alim examinations when some students, loyal to Principal Sirajuddoula, took her to the roof and set her on fire, her brother claimed.
The madrasa has been shut down until April 17, after the incident grabbed the headlines and sparked outrage across Bangladesh.