Police in India's capital Delhi have registered a complaint against a girls' school where 16 students were locked up in the basement for five hours.
The girls were reportedly detained because their parents had not paid the school fees.
All the detained girls are kindergarten students and are believed to be between four and six years old.
School officials told local media that the students were kept in an "activity centre" but did not comment further.
Parents say they found out their daughters were being detained when they went to the school to pick them up but did not find them in the classroom.
According to the police complaint lodged by the parents, the girls were in the school's basement from 7.30am to 12.30pm.
The parents alleged that it was very hot in the basement and that the girls were "hungry and thirsty".
"We will be able to name the people responsible for the children's ordeal after our investigation concludes," a police official told the BBC.
Some parents have said they had already paid the school fees. "Even after I showed the proof, the principal was not apologetic or remorseful," a parent told Indian news website NDTV.
The Delhi Commission for Protection of Child Rights has reportedly set up an inquiry.