Around 70 girls were forced to take their clothes off at a school in India, so a warden could check who was menstruating.
The group were also allegedly made to sit in a classroom whilst naked at Kasturba Gandhi Residential School in Uttar Pradesh, according to NDTV.
District education officer Chandrakesh Yadav said parents had alleged the children were forced to comply as they were threatened with dire consequences if they did not.
One pupil said: "There was no teacher around. We were called downstairs [from our rooms]. Madam made us take off our clothes, saying she will beat us if we did not.
"We are kids, what could we do? She would have beaten us had we not obeyed her."
Parents also claimed the warden "often hits the girls and blackmails them" and have called on the government to punish her.
An investigation into the incident has now been ordered by the state government.
Yadav said: "We have taken prompt action. A five-member team has been formed. They are investigating the case and the warden will be removed soon. There is zero tolerance towards such acts."
However the warden has denied the allegations, saying: "No one asked them to remove clothes. This is a conspiracy by the staff because they do not want me to stay here. I am strict, that is why they hate me."