Violence broke out in Tamil Nadu’s Kallakurichi district on Sunday during a protest to seek justice in the case of a Class 12 girl’s death, PTI reported.

The 17-year-old girl was a student at a private residential school in the district’s Chinnasalem town. She was found dead on July 13 on her hostel premises.

A post-mortem examination showed that she had sustained injuries before her death, The New Indian Express reported. The girl’s parents and other relatives alleged that there was foul play in her death and refused to receive her body.

Protestors on Sunday stormed the school and set buses on fire. Some agitators also burned a police vehicle.

Over 20 police personnel, including Deputy Inspector General of Police M Pandian, sustained injuries in the violence, The Times of India reported.

Director General of Police C Sylendra Babu said that the officers had to baton-charge protestors as they turned violent, ANI reported. He added that 500 police personnel have been sent to the area to maintain law and order.

“We want to arrest all accused who attacked a school, no one would be spared,” Babu said. “We have videos as well.”

Section 144 of the Code of Criminal Procedure, which bans the assembly of four or more persons, has been imposed in the taluks of Kallakurichi, Chinnasalem and Nainar Palayam.

Tamil Nadu Chief Minister MK Stalin urged citizens to maintain peace. He said that he has asked the director general of police and home secretary to go to Kallakurichi, and added that accused persons in the case related to the girl’s death will be punished.

Opposition leaders, including the All India Anna Dravida Munnetra Kazhagam’s Edappadi K Palaniswami, have demanded an investigation into the death.