Sri Lankan authorities have launched three separate investigations after a deadly prison riot left at least 26 people dead, including seven prison officials and 19 inmates, in one of the country’s deadliest prison incidents in recent years.

The violence erupted at a prison in Negombo, about 35 kilometers (22 miles) north of the capital, Colombo.

According to officials, unrest began on Sunday with clashes between rival groups of inmates before escalating on Monday when prisoners turned on correctional officers attempting to restore order.

Authorities said some inmates also attempted to breach the prison’s main gate but were prevented from escaping.

Justice Minister Harshana Nanayakkara described the violence as a “tragic incident” and said 77 people remain hospitalized, including 23 prison officers and 54 inmates.

He did not disclose the causes of the fatalities or provide details about the victims’ injuries.

Speaking before Parliament on Tuesday, Nanayakkara announced that three investigations had been launched into the incident.

The inquiries include a police investigation, an internal review by the prison department and an independent committee headed by a retired judge.

The minister said investigators will examine the causes of the violence, determine whether security failures contributed to the unrest and assess whether severe overcrowding within the prison system played a role.

“Our responsibility is to prevent such incidents from happening again,” he said.

According to Nanayakkara, the initial confrontation involved rival gangs linked to the illegal drug trade.

After authorities regained control of the prison on Monday evening, inmates believed to have led the violence were transferred to other correctional facilities.

Television footage broadcast on Tuesday showed hundreds of anxious relatives gathered outside both the prison and nearby hospitals, seeking information about family members caught up in the unrest.

Many were seen crying and pleading with officials for updates.

Security has since been significantly reinforced around the prison, with additional military personnel and armored vehicles deployed to prevent further disturbances.

The tragedy has also renewed attention on chronic overcrowding in Sri Lanka’s prison system.

Officials say the country’s correctional facilities currently house more than 39,000 inmates despite having a combined capacity of only about 10,000, placing enormous strain on prison infrastructure and security.