Seven inmates were killed in a notoriously overcrowded prison in Bolivia on Wednesday when police stormed the penitentiary.
About 2,000 officers raided Palmasola jail in Santa Cruz before dawn.
The move followed a prison uprising last week by inmates disgruntled over the removal of certain privileges.
Police chief Alfonso Mendoza said there had been "complete lawlessness" inside the jail, which has the reputation for being one of Bolivia's most violent.
More than 5,200 people are held in Palmasola, but only a few hundred have been sentenced. The others are awaiting trial.
Deputy Interior Minister Jose Luis Quiroga said the inmates had been "resisting the police incursion" with firearms.
Police said they had regained control of the prison after seizing vast amounts of drugs, alcohol and weapons.
The prison uprising started nearly 10 days ago, after the Bolivian government banned children younger than six from visiting jailed relatives.
Pope Francis visited Palmasola in 2015 and met inmates who complained about inhuman conditions inside the prison.