A ninth-grade female student was rescued from a school washroom in Digholia upazila with her hands, legs and mouth tied, nearly five hours after classes ended on Thursday.

The incident took place at Gazirhat Hazi Naimuddin High School, confirmed Officer-in-Charge (OC) of Digholia Police Station Hawlader Sanwar Hossain Masum.

OC Masum said an initial investigation suggested that two people remained near the washroom after school hours.

Police suspect they may have taken advantage of the empty school premises and struck the girl on the head and tied her up inside the washroom.

The OC said the girl later regained consciousness and began making noises, which alerted the construction workers.

He said the girl later told her relatives that she did not know the attackers.

According to school authorities and local residents, classes ended around 4:00pm, after which teachers, staff and students left the school premises.

Around 9:00pm, workers engaged in construction work at the school heard unusual sounds coming from a locked washroom.

Suspecting that someone might be inside, the workers went to the washroom and heard a girl moaning. They broke open the lock and found the student lying inside with her hands, legs and mouth tied.

The workers rescued her and took her to the chamber of local physician Mofizur Rahman Shafin, where she received first aid. She was later shifted to a private hospital in Khulna after her condition deteriorated.

The girl's mother alleged that someone struck her daughter on the head from behind when she entered the washroom after classes. She claimed the attackers then tied the girl's hands, legs and mouth and left her inside.

She also alleged that the girl was injected with an unidentified substance and sustained blade-like cuts on different parts of her body.

Police said the details of the incident and the identities of those responsible have yet to be established.

Police were also investigating whether the incident was linked to a possible money dispute dating back to the time when the girl's father ran an NGO several years ago.

“We are investigating who committed the incident and why. Those responsible will be brought to justice as soon as possible,” said OC Masum.