For five days teenage offenders have run riot in a Sao Paulo jail, destroying everything in their path. They have taken hostages, committed arson and carried out exceptionally brutal murders.
Yesterday they announced that more violence is to come.
Children as young as 12 have taken part in the rampage, ao Paulo - South America's largest city - that has left leaving four dead, 48 wounded and three buildings destroyed.
Febem - the State Foundation for the Well-Being of Minors - houses over 800 juvenile offenders and is notorious among human rights campaigners for its appalling conditions. However, the unprecedented scale of mob rule has left even Sao Paulo's state governor admitting things are now out of control.
At an emergency meeting, the federal government's Commission of Human Rights yesterday approved the closure of Febem.
Ms Rita Camara, a commission spokeswoman, said: "We need a complete overhaul of the way the country deals with teenage offenders. The current system does not meet any of their needs. We have to start from zero."
But rights activists say that the unwieldy Brazilian bureaucracy could take years to implement reforms.
Prof Paulo Sergio Pinheiro, director of the Centre for Study of Violence at Sao Paulo University, said: "I'm very sceptical that anything will be done because this is the way that Brazil deals with the poor and with black people."
The families of the teenagers still locked in Febem have been on a vigil outside the institution's gates ever since the riots erupted on Saturday night.
Although some inmates have been transferred to other detention centres, at least 800 remain inside.
Officials say that the teenagers now have no mattresses to sleep on, no showers and have to urinate in plastic bottles. "They have destroyed everything," said a military police spokesman. "They burnt the mattresses and ripped out all the plumbing."
One mother, whose 17-year-old son was convicted for car theft, said: "I'm not going to leave here until I know he is all right The authorities haven't told us anything. If he could escape I would run away with him and we could start life again."
Yesterday, one of the four teenage inmates murdered by the mob was buried. He was killed because he tried to protect a staff member who was held hostage for four days.
"He died trying to save me," said the warden. "I saw the others beat him to a pulp and then cut his body up with an axe. They threw his limbs and head to the police outside Febem and then put his remains on the fire. They laughed when they saw his skin explode with the heat. It was horrible."
This week's violence comes after the teenagers' demands for regular visiting hours and the right to wash their clothes were ignored by detention centre staff. They were also protesting over planned strike by state employees that would have meant military police taking control of Febem.
Young offenders over the age of 12 are sent to one of 74 detention centres in Brazil. The vast majority have committed crimes against property, while 20 per cent are sentenced for crimes against a person. Only eight per cent are convicted for serious violent crimes.
"Mixing children who have only committed petty crimes with those who belong to violent gangs is a recipe for disaster," said Prof Pinheiro.
Last month, 1,000 young offenders escaped from Febem in a mass jail-break after protests about living conditions were ignored.