Shashank Mishra took the girl, a student of class-II in Kids Convent school, to a field after school hours and raped the girl before killing her at Bairia area yesterday, they said.
When the girl did not return home, her family started searching her. They found her dead in the field, police said.
On the basis of suspicion, locals thrashed Mishra, who later admitted to the crime, they said, adding that the teacher has been arrested.
