At least 31 people have been injured in clashes between guards and riot inmates at a prison in the Sri Lankan capital, hospital officials say.
Most of the offended are prisoners who were shot by guard. Police forces deny claims that three inmates were killed.
Several buildings were set alight in the remand wing of Colombo's main prison before order was restore.
Prisoners say they desire better food and conditions. Police force said inmates were angry at moves to curb drug smuggling.
The head of Sri Lanka's prisons department admitted that the treatment of prisoners in the jail fell short of suitable standards.
A local resident told the Associated Press news agency that disturbances had been going on for numerous days.