The Minister in charge of Sri Lankan prisons, Chandrasiri Gajadheera, told reporters on Wednesday that a special investigation has been launched into the prison riot.
The police said that the number of people injured in the riots had risen to 31 by Wednesday, most of who were prisoners suffering from gun shot wounds.
Gajadheera said that prison guards had opened fire only after the prisoners had ignored warnings and attacked some of the guards.
The prisoners, who were initially believed to have been protesting over the food served at the prison, had been demanding the removal of a senior officer at the prison.
Gajadheera said that most of the inmates involved in the riot were jailed over drugs related offences and they had at times attempted to smuggle drugs into the prison.
During the riot the prisoners pelted stones at the prison guards and the police as well as firefighters who had attempted to douse flames at a prison building.
Several documents related to the inmates were stored in the building which was set on fire by the prisoners, Gajadheera said, adding that attempts will be made to recover the information from past court documents.