The head of Bolivia’s penitentiary system, Tomas Molina, believes this situation is unique in the region.
Under the country’s legislation, children under six years are allowed to stay in their parents’ cells.
However, Mr Molina acknowledges that they normally remain in jail until they are much older “because nobody else can care for them”.
In the detention centre of San Pedro – the most populated male prison in Bolivia’s main city, La Paz – there are 200 children.
“We have not had any problem with them. There is a sort of internal pact that, if an inmate harms a child, he is likely to face difficulties in the prison,” says San Pedro’s director, Ramiro Ulloa.
Children in that jail receive meals and education under a government-sponsored programme. They are also supervised by humanitarian groups.
Inside the women’s prison in La Paz’s district of Obrajes, little boys and girls wander freely in the yard as if they were playing at school during a parents’ meeting.
The jail’s director, Celida Vera, says that more than 260 female inmates live there alongside 70 children.
Many women have more than one child, and families sometimes have to share very small cells.
One of the inmates, Briseida, says that she had to explain her son Carlos Patricio, 9, why she was in prison.
“I told him that I had misbehaved.”
Most of the children in Obrajes do not why they live there. Many were born behind bars.
Overcrowding seems to be worse in the Palmasola prison, in the eastern city of Santa Cruz, which holds entire families. Palmasola is considered one of the most dangerous jails in the country.
Around 400 women are reportedly living there.
“It is like a town”, says Tomas Molina.
Living conditions are no better in the central region of Cochabamba, where the female detention centre of San Sebastian also holds a number of children.
Alejandra Canelas, a psychologist working in a child day-care centre attached to the jail, claims that youngsters frequently witness violence and even prostitution in the cells.
According to the Bolivian authorities, the number of children living in prisons has increased since the 1980s, when the government took a tougher line against drug-trafficking.
Entire families ended up in jail because children had nowhere to go when their parents were arrested.
In one case, after a police operation in Cochabamba, one family reportedly took their parrot and a dog to prison because they did not want to leave them behind.
The head of Bolivia’s penitentiary system believes that the presence of children in the country’s jails is not a big problem.
“They would otherwise be on the streets facing the dangers of crime,” he says.
But Ms Canelas is not entirely convinced. She says that authorities should be concerned about these boys’ and girls’ future in society. BBC