The victim was allegedly raped by one Yogendra Yadav, 20, while she was going to call her father working in the field, Additional Superintendent of Police Balendu Bhushan Singh said.
The girl has been admitted to a hospital in Bareilly where her condition was stated to be serious, Singh said.
A case has been lodged against Yadav and his two accomplices, he said, adding efforts were on to nab them.