Parents of two siblings studying in Sheth NL High School in Malad have approached the police alleging that their wards were confined inside a classroom for over three hours by a teacher as punishment on Wednesday. An FIR was filed against the teacher Thursday. Malad police said the father of a 9-year old boy in Class V and a 13-year-old girl in Class VIII of the school approached them. “The father has alleged that the two siblings were playing in the school compound during recess and accidentally caused another student to fall down and hurt himself. The student complained to a teacher who was passing by. The teacher allegedly locked the brother and sister inside a classroom around 3 pm. The father alleged that the teacher left school at 6 pm and forgot to unlock the two students. Around 6.30 pm, a PT instructor heard the students’ knocking and unlocked the room,” said assistant inspector Vinod Patil.