Fire erupted at the Georgetown Prison after a number of inmates set fire to a mattress in an ongoing unrest there Sunday night.
Three fire tenders arrived on the scene but only one went into action at the John Street (eastern) end, closer to the source of the blaze.
Even after the fire was extinguished, fire fighters were seen tinkering with a hydrant at the corner of John and Bent Streets.
Policemen with shields and helmets were at the same time seen entering the prison to boost their presence.
Loud intermittent noises by inmates were heard.
Well-placed sources said the unrest began about 6 PM when prison wardens began searching for an object that was thrown over the Camp Street fence.
The inmates reacted angrily and began banging the building, prompting the deployment of riot squad police to quell the unrest.