Several detainees attempted to escape during the commotion and prison guards had to open fire trying to control the situation.
Police said no inmates had been able to escape in the incident and extra security has been deployed at the prison premises.
Sri Lanka is under curfew since Friday evening after a total of 77 COVID cases have been tested positive so far. The curfew was enforced in a bid to minimize public gatherings in order to contain the spread of COVID-19.
Around 200 persons have been arrested for violating the curfew. Meanwhile, 298 Sri Lankans who had gone on pilgrimage to India, returned last night on a special flight and were sent on two weeks quarantine.
Colombo airport is closed for arrivals till Wednesday but departures are allowed. In related development, some leading hotels have offered to be used as quarantine centres to the government, if the need arises. There are around three thousand people in quarantine who had returned from abroad.