Several students who went to their classes after having breakfast in the morning suddenly started feeling uneasy and began vomiting in the afternoon.
State general education minister V Sivankutty also announced the completion of the distribution of 29,000 Robotic Kits in schools.
The class teacher, Gorakhnath Maruti Joshi, took students to the house of the headmaster Tukaram Govind Sable (53), who allegedly raped the teenager and sent her home, says police.
Uttar Pradesh chief minister Yogi Adityanath asks parents to send their children to school so that they can take advantage of the new facilities such as computer, online smart classes, including a modern science laboratory.
Himachal Pradesh Chief minister Sukhvinder Singh Sukhu also distributed tablets and travel kits to the students before their departure.
Secondary schools in Prayagraj have been closed for physical classes. Teachers have been asked to report to schools for practical, home exams.