A teenage girl in India's eastern state of Bihar complained she was raped by students and teachers, including the principal, for over seven months at her school, police said Saturday.

The 13-year-old in her police complaint said she was blackmailed and gang-raped by the accused for the past seven months, China's Xinhua news agency reported.

"The girl in her complaint has mentioned that she was raped for seven months by 18 people, which include 15 students, two teachers and her school principal," a police official said.

"The sexual exploitation according to the victim started in December last year after her father was jailed."

Police officials investigating the case have arrested a teacher and school principal, and detained two students for questioning, local media reports said.

The girl said her ordeal continued until her father was released from jail, following which she approached the police with the complaint.

"The complaint was registered based on the girl's statement taken at a women's police station," a police official posted in Chhapra town of Saran district said. "We are looking out for the others named in the complaint."

Authorities have taken the girl for medical examination and formed a medical board in this regard.

Sexual attacks on women and girls in India puts a question mark on their safety.

In December 2012 a fatal gang-rape of a medical student in New Delhi brought spotlight on crimes against women in India.

The incident saw huge protests and resulted in new anti-rape laws in the country. However, brutal sexual attacks against women and girls continue to be reported across India.

- Bernama