Clashes broke out inside a prison in the outskirts of Sri Lanka’s capital, killing at least 25 people and injuring more than 100, officials and a TV station reported Monday.

Police said the unrest at the prison in Negombo, about 35 kilometers (22 miles) north of the capital, Colombo, began on Sunday and continued on Monday.

The current death toll stands at 25, which includes both inmates and six prison officials. More than 100 individuals have been admitted to hospitals with gunshot wounds, cuts, and severe bruises.

Preliminary findings indicate the initial conflict erupted between rival groups of inmates, reportedly linked to opposing factions over drug trafficking activities within the facility. The fight involved long-term convicted criminals and temporary detainees.

On Monday, inmates reportedly seized prison weapons. They turned on guards trying to intervene and attempted to escape before being contained. Female inmates also staged a rooftop protest during the unrest, leading to a partial roof collapse that caused further injuries.

The Sri Lanka Police Special Task Force (STF) and riot squads have taken full control of the prison. The military and air force remain deployed on standby around the perimeter to ensure security. Authorities are now transferring some inmates to other facilities and conducting a formal investigation.

This tragedy highlights severe ongoing issues with prison congestion in Sri Lanka, where the national prison system holds over 39,000 inmates despite a total capacity of only 10,000.