After negotiations with the police, a number of them were allowed to leave in getaway cars; however, several of the prisoners were killed after being pursued by police. Our Brazil correspondent, Stephen Cviic, reports.

The attempted escape began during a Christmas Eve celebration at the Paulo Sarasate Penal Institute when a group of prisoners seized four hostages and demanded to be allowed to leave.

One of the inmates was shot dead in an exchange of fire with prison guards but later, after a day of tense negotiations, the hostage-takers were told they could leave the jail. It appears that the police even went so far as to provide the prisoners with guns, ammunition and getaway cars. As the vehicles left the prison with three of the hostages still being held as human shields, the police gave chase.

At least one of the cars crashed, killing some of its occupants. Several other prisoners were shot dead. It's these shootings which have caused controversy. According to the police, the inmates - who they say were all violent criminals - were killed in an exchange of fire.

However, the president of the Human Rights Commission of the local Legislative Assembly has described it as a massacre, saying that some of the prisoners were shot by police when they were in a hopeless position, after their vehicles had crashed.

The three hostages were also injured, none of them seriously.