Parents laid siege to a government-aided middle school at Kasavanampatti near here on Thursday, demanding action against the headmaster, who reportedly canned three students.

The school did not function from the morning itself as the parents refused to send their children to school. The injured — all seventh class students — were admitted to the Government Headquarters Hospital in Dindigul. Dhanalakshmi, mother of one of the injured students, said that the headmaster had ordered the students to pay a fine of Rs. 50 each for damaging the ring ball on Wednesday evening. When they expressed their inability to pay the fine, he reportedly caned them.