The Uttar Pradesh Police are investigating the death of prisoner at the Fatehgarh district jail due to a bullet injury, The Times of India reported on Tuesday.

Shivam, 30, had been injured on Sunday during a protest by inmates that turned violent. He reportedly died during treatment at a district hospital.

The prisoners were protesting against the death of another inmate named Sandeep Yadav, allegedly due to negligence of the prison staff. But the police claimed that he died at a hospital during treatment for dengue on Saturday.

Upset about Yadav’s death, the prisoners had allegedly attacked jail officials and started a fire in the prison on Sunday morning. Thirty police officers were injured in the chaos.

The police have denied firing at the inmates to control the situation, the Hindustan Times reported. But in a purported video, Shivam claimed before his death that he had been shot by a jailor, The Indian Express reported.

Shivam’s autopsy report also showed that he died because of a bullet injury, an unidentified police officer and a doctor told the Hindustan Times. “The bullet ruptured the vital organs, and there was excessive loss of blood,” they added.

Director General (Prisons) Anand Kumar said he was aware of the autopsy report. “A committee of three senior officers of jail administration has been formed to probe the incident leading to the death of inmate Shivam,” Kumar told The Times of India.

Kumar said strict action will be taken against whoever is guilty. “It would be investigated as to how the bullet and the firearm reached inside the jail and who shot the prisoner,” Kumar added.