Some relatives briefly scuffled with the police Footage of the riot

At least 32 inmates died and six were injured in a blaze during an uprising at a jail in Magdalena, south-east of the capital.

Nine bodies have not been identified, said Buenos Aires province Justice Minister Eduardo Di Rocco.

The blaze was started during a fight, when prisoners set mattress and blankets on fire.

The smoke and flames spread quickly.

Mr Di Rocco said most of those killed died from asphyxiation, but some of the bodies also had knife wounds sustained during the fight. A prison warden received serious head injuries.

The bodies were taken to the jail chapel for identification. Hundreds of families gathered outside the prison desperate for news of jailed relatives, and there were some scuffles with the police.

Protest

An investigation into the uprising is under way.

Earlier there had been a protest at the prison demanding better conditions and longer visiting hours for Mother's Day, but the authorities deny the fire was started as part of the protest.

The BBC's Tom Gibb in the region says riots and fires are increasingly common in Argentina's jails, as they are in the rest of Latin America.

The prisons have become overcrowded in the last decade and the country has faced a serious crime wave following the collapse of the economy four years ago.