The imprisoned pupils were eventually freed by their parents, who broke open the doors when they heard them screaming, the Hindustan Times reported.

Nearly a dozen pupils fainted during the ordeal in the school, in the northern state of Uttar Pradesh. The report said the headmistress, furious over losing 500 rupees (S$15.80) been suspended.

In another incident in central India, a 13-year-old schoolgirl was allegedly burnt alive by three of her classmates after she complained about the bullying of another pupil, the newspaper reported.

The report said after she reported the bullying to teachers, she was followed home by the bullies, doused in kerosene and set alight. She died later in hospital, the paper said. -- AFP