About 12 people were taken hostage at the Reclusorio Sur Prison in the south of the city during visiting hours on Christmas Day by prisoners demanding their freedom.

The inmates took advantage of Christmas privileges and started a riot as part of an escape attempt.

When the guards managed to stop the break-out, four inmates seized hostages, including several visitors.

About 600 heavily-armed police fired tear gas in a bid to quell the disturbance and hundreds of staff and visitors, including many children, were evacuated.

The prison was then sealed off and the police withdrew.

After all-night negotiations with prison officials three armed inmates who were still holding prisoners surrendered. A fourth inmate had given himself up earlier.