Riots at a prison in western Sri Lanka have killed 26 people, seven of them guards, and injured more than 100.

The two days of violence at Negombo prison, in a coastal town north of Colombo, began with clashes between two groups of inmates.

The prisoners apparently grabbed the guards’ weapons on Sunday. That day two people died and dozens were injured. Later, groups of male and female prisoners from an adjoining unit climbed onto the prison roofs demanding to be released.

Fresh violence broke out on Monday when inmates tried to rush into the prison gates. Security forces were deployed and multiple gunshots were heard from inside the prison.

The violence was reportedly sparked by a confrontation because an inmate reported a drug trafficking operation inside.

A total of 23 correctional officers and 54 inmates continue to receive treatment, officials said.

Some of the injured were taken to Negombo hospital. The hospital director told the AFP news agency that some had gunshot wounds, while others had serious cuts and bruises. Others were taken to the National Hospital in Colombo.

Police said part of the prison roof collapsed during the incident, causing injuries to some of the women involved, AFP reported.

Crowds of inmates’ relatives gathered outside Monday as the situation unfolded. Some told the BBC in Sinhalese that they had not been given information about where their relatives were or who was alive and who had died.