JOIN USInitial reports said 14 prisoners and six guards suffered injuries in Tuesday's disturbance.
The updated casualty figures were provided by the regional director of the Gendarmeria prison service, Rene Salcedo, who said inmates rioted to demand the restitution of conjugal visits and other privileges that were suspended nationwide after 81 inmates died in a Dec 8 fire at Santiago's San Miguel Prison.
About a hundred disgruntled inmates managed to get onto the roof of the Antofagasta prison, where they burned mattresses and hurled stones at people below.
It took the Gendarmeria and a contingent of Carabineros - Chile's militarised police - about three hours to bring the situation under control and move the rioters to an isolated area of the prison, Salcedo said.
Four inmates were hurt badly enough to require treatment at the Regional Hospital in Antofagasta, while the guards received only slight injuries.
One officer was hurt when inmates' families gathered outside the prison threw rocks at the gate.
Roughly 800 of the 1,300 inmates at the Antofagasta facility have been on hunger strike since the deadly blaze at San Miguel, according to sources in the Gendarmeria.
The tragedy at San Miguel, in which overcrowding was a major factor, has spurred protests of various kinds at prisons throughout Chile.
Overcrowding also played a role in Tuesday's uprising in the Antofagasta prison, Salcedo said, noting that the facility currently houses roughly double the 680 inmates it was built to hold.